Plants, Allergens, Irritants and creatures of dermatologic significance Flashcards
1- You diagnose a patient with scabies and she tells you that her only allergy is to sunflowers. Which of the following medications should be avoided in her?
A. Ivermectin
B. Malathion
C. Lindane
D. Permethrin
E. Precipitated sulfure
Correct choice: D. Permethrin
Explanation: Patients with allergies to plants in the Asteraceae or Compositae family (chrysanthemum, ragweed, sunflower, artichoke, arnica, daisy, and marigold) should not be given permethrin, as it may cross react. The relevant potential allergen is sesquiterpene lactone. The remaining answer choices will not cross react in a patient with a sunflower allergy.
2- This insect transmits which of the following diseases?
A. Zika
B. Malaria
C. Chikungunya
D. Yellow fever
E. Dengue
Correct choice: B. Malaria
Explanation: Malaria, the most common parasitic disease in the world, is transmitted to the human host by mosquitoes of the genus Anopheles. Mosquitoes of the genus Aedes transmit the remaining answer choices.
3- Which of the following is the most common cause of irritant contact dermatitis in florists?
A. Calcium oxalate
B. Mechanical dermatitis
C. Tuliposide A
D. Primin
E. Sesquiterpene lactones
Correct choice: A. Calcium oxalate
Explanation: Calcium oxalate is present in the bulbs and stems of Narcissus (daffodil), the most common cause of irritant contact dermatitis in florists. The other listed choices are not the most common cause of irritant contact dermatitis in florists.
4- A patient presents with hyperpigmentation on the leg. What is the most likely culprit?
A. HCV
B. Vinegar
C. Tomato Juice
D. Garlic
E. Lime
Correct choice: E. Lime
Explanation: This is an example of phytophotodermatitis. The linearity indicates an “outside job,” and appears as though something dripped down this patient’s leg. Given the morphology it is likely that this is a phytophotodermatitis. Lime (Rutaceae family) would be the most likely culprit of all of the options. Vinegar, tomato juice, and garlic are not psoralens and do not cause phyotophotodermatitis. HCV is a distractor and does not cause phytophotodermatitis.
Reference: Bolognia text: Chapter 17. Derm-in-Review Study Guide - Chapter 14 (pg 467-468).
5- Which of the following is true regarding Babesia microti, which causes Babesiosis?
A. Is pathogenic in an infection that is endemic in Ohio
B. Is an extracellular parasite
C. Is transmitted by Ixodes dammini
D. Infection is usually asymptomatic
E. The anemia caused by infection is microcytic
Correct choice: C. Is transmitted by Ixodes dammini
Explanation: Babesiosis is caused by an intracellular RBC parasite, Babesia microti. It is transmitted by the larvae of Ixodes dammini. It is an intracellular parasite. This disease is endemic in eastern Long Island, Martha’s Vineyard, and Nantucket, and carries an increased risk in those with T-cell depression or after splenectomy. The condition is associated with fever, drenching sweats, myalgias, and hemolytic anemia.
6- Which of the following may be transmitted via this insect?
A. Lyme Disease
B. Rocky Mountain Spotted Fever
C. Tularemia
D. Anaplasmosis
E. Babesiosis
Correct choice: C. Tularemia
Explanation: The insect pictured is the Lone star tick (Ambylomma americanum). Females have a characteristic dorsal white patch. Bites from this tick can transmit Ehrlichiosis, Heartland virus, Southern tick-associated rash illness (STARI), and Tularemia.
7- All of the following plants commonly cause a phytophotodermatitis except:
A. Hawaiian lei flowers
B. Ficus carica
C. Celery
D. Ananas comosus
E. Burning bush
Correct choice: D. Ananas comosus
Explanation: Ananas comosus (pineapple) commonly produces irritant contact dermatitis as it contains both bromelin and calcium oxalate. It is not known to cause phytophotodermatitis. Hawaiian lei flowers (mokihana), Ficus carica (fig tree), celery, and burning bush (Dictamnus) all are known to commonly cause phytophotodermatitis.
8- Which of the following is NOT a common cause of seabather’s eruption?
A. Edwardsiella lineate
B. Linuche unguiculata
C. Thimble jelly fish
D. Sea anemone
E. Schistosoma douthitti
Correct choice: E. Schistosoma douthitti
Explanation: Schistosoma douthitti may cause “Swimmer’s itch” (aka cercarial dermatitis). This is a condition contracted in natural bodies of water, when people are exposed to skin-penetrating, larval flatworm parasites of the family Schistosomatidae, that emerge from aquatic snails. Swimmer’s itch is a globally-distributed, allergic condition. Clinically, the dermatitis involves exposed body surfaces, which distinguishes it from seabather’s eruption. Seabather’s eruption (or sea lice) can be sporadic or part of an outbreak. Clinically, it appears as dermatitis beneath areas covered by swim suits. The geographic distribution is most frequent from the Caribbean to Bermuda, however there have been three outbreaks at Long Island, NY beaches. A variety of cnidarian larvae can cause this eruption, including thimble jelly fish (Linuche unguiculata) and sea anemone (Edwardsiella lineate). Quick removal of bathing suits and rinsing can help with prevention. Symptom relief is the mainstay of therapy.
9- Flying squirrels can carry many infections, including which of the following?
A. Epidemic typhus
B. Staphlyococcus sp
C. Toxoplasma gondii
D. Staphlyococcus sp and epidemic typhus
E. Staphlyococcus sp, toxoplasma gondii and epidemic typhus
Correct choice: E. Staphlyococcus sp, toxoplasma gondii and epidemic typhus
Explanation: Flying squirrels can carry many infections, including Toxoplasma gondii, Staphylococcus sp., and Rickettsia prowazekii (via the body louse, causing epidemic typhus). Flying squirrels can carry many infections, including Toxoplasma gondii, Staphylococcus sp., and Rickettsia prowazekii (via the body louse, causing epidemic typhus).
10- This patient tells you that he recently returned from a hiking trip and now has this intensely itchy blistering rash. Which of the following is the most likely cause of his rash?
A. Pentadecacatechol
B. Tuliposide A
C. Myroxylon balsamum
D. Diallyl disulfide
E. Colophony
Correct choice: A. Pentadecacatechol
Explanation: The most likely diagnosis is allergic contact dermatitis, which most commonly occurs due to Toxicodendron (poison ivy, poison oak, poison sumac) exposure. The sensitizer is pentadecacatechol which is in the urushiol. Tuliposide A is the sensitizer in the peruvian lily, tulips, and hyacinths. Colophony is the sensitizer in the resin of Pine trees. Balsam of peru is from the myroxylon balsamum tree. Diallyl disulfide is the sensitizer in chives, onions and garlic.
11- Which plant is pictured?
A. Poison ivy
B. Poison oak
C. Poison sumac
D. Arnica
E. Primrose
Correct choice: B. Poison oak
Explanation: This is an image of poison oak, which characteristically arranges its leaves in triplet. Poison ivy does this commonly as well, but it can be differentiated based on the fact that the tips of poison ivy’s leaves are more pointed whereas those of poison oak are more rounded. Poison ivy, poison oak, and poison sumac are the most common causes of clinically diagnosed allergic contact dermatitis in North America. Approximately 50% to 75% of the US adult population is clinically sensitive to poison ivy, oak, and sumac. Poison sumac typically arranges its leaves in largers groups (7-11) than poison ivy or oak. Arnica and primrose look quite distinct from poison oak and thus are easily differentiated.
12- Which of the following plants DOES NOT contain thiocyanates that can cause an irritant dermatitis?
A. Garlic
B. Mustard
C. Radish
D. Plants of the Brassicaceae family
E. Parsley
Correct choice: E. Parsley
Explanation: Parsley contains furocoumarins, which produce phytophotodermatitis. Parsley does not contain thiocyanates. Thiocyanates are found in garlic (Alliaceae family), mustard, and radish (Brassicaceae family).
13- This insect transmits which disease?
A. Lyme disease
B. Ehrlichiosis
C. Babesiosis
D. Rocky Mountain Spotted Fever
E. African Tick Bite Fever
Correct choice: D. Rocky Mountain Spotted Fever
Explanation: This is an image of a female Dermacentor variabilis tick (note the reddish-brown dorsal coloration with whitish markings on the upper body aka scutum), otherwise called the American dog tick. Bites from this tick may transmit Rickettsia rickettsii, the causative bacterium of Rocky Mountain Spotted Fever. Ticks from the Ixodes genus may transmit Lyme Disease, Babesiosis, and/or Ehrlichiosis. Ticks from the Ambylomma genus may transmit African Tick Bite Fever (as well as RMSF, Lyme, and Ehrlichiosis in the case of Ambylomma americanum, aka the Lone star tick).
14- A florist presents with chronic fingertip dermatitis that is determined to be allergic in origin. Occupational exposure to which of the following plants is the most likely cause?
A. Chrysanthemum
B. Sunflower
C. Daffodil
D. Tulip
E. Primrose
Correct choice: D. Tulip
Explanation: Tulips are one of the most common causes of occupational allergic contact dermatitis (ACD) in florists.
This question assesses the examinee’s knowledge of occupational plant ACD. Florists commonly develop dominant hand fingertip dermatitis following sensitization to tulipalin A/B in tulip bulbs (choice 4). Chrysanthemum (choice 1) and sunflower (choice 2), containing sesquiterpene lactone, cause ACD in florists less frequently than tulips. Daffodils (Narcissus spp., choice 3) contain calcium oxalate and are the most common cause of irritant contact dermatitis in florists. Primrose (choice 5) is another cause of ACD in florists, but not as often as tulips; the allergen is primin.
15- This organism is:
A. Pediculus humanus
B. Pulex irritans
C. Chigoe flea
D. Pediculus capitis
E. Pthirus pubis
Correct choice: E. Pthirus pubis
Explanation: This is a crab louse. It is shorter and wider than the head and body louse. Note the crab-like claws.
16- This creature can spread which of the following diseases?
A. Endemic typhus
B. Epidemic typhus
C. Scrub typhus
D. Q fever
E. Erlichiosis
Correct choice: B. Epidemic typhus
Explanation: The human body louse can transmit Rickettsia prowazekii , which is responsible for epidemic typhus.
17- A patient presents with chronic fissuring of the first three fingertips of his non-dominant hand. He works in a restaurant kitchen. Which of the following is the most likely cause of his dermatitis?
A. D-limonene
B. Diallyl disulfide
C. Primin
D. Tuliposide A
E. Sesquiterpene lactone
Correct choice: B. Diallyl disulfide
Explanation: In food handlers, sensitization to diallyl disulfide from chopping garlic and onions causes a characteristic dermatitis of the first three digits of the non-dominant hand.
This question tests the examinee’s knowledge of plant allergic contact dermatitis and the association of non-dominant fingertip dermatitis with garlic/onion chopping. Food preparers chopping garlic and onions can become sensitized to diallyl disulfide (choice 2), leading to distinctive fissuring and hyperkeratosis of the first three fingers of the non-dominant hand. The other choices are not associated with food handling. D-limonene (choice 1), the allergen in tea tree oil, does not produce a unique hand dermatitis. In gardeners or florists, dermatitis caused by primin (choice 3) from primroses and tuliposide A (choice 4) from Peruvian lilies tends to affect the dominant hand. Sequiterpene lactone (choice 5), found in members of the Asteraceae (Compositae) family, is the most common plant allergen, but does not typically cause dermatitis in food handlers.
18- The pictured plant is a member of which family?
A. Alliaceae
B. Primulaceae
C. Toxicodendron
D. Compositae
E. Alstromeria
Correct choice: D. Compositae
Explanation: This is a photo of ragweed, a member of the compositae (or asteraceae) family. Ragweed is not a member of the other listed plant families.
19- What is the sensitizer for this flower?
A. Sesquiterpene lactone
B. Primin
C. Diallyl disulfide
D. Tuliposide A
E. Pentadecylcatechol
Correct choice: D. Tuliposide A
Explanation: This is a peruvian lily which has tuliposide A as its sensitizer. Poison ivy’s sensitizer is pentadecylcatechol which is in the urushiol. Sesquiterpene lactone is the sensitizer for the asteraceae family. Diallyl disulfide is the sensitizer for the alliaceae family which includes onions and garlic. Primin is the sensitizer for the primrose.
Peruvian lily: Tuliposide A, the biosynthetic precursor of the allergenic lactone tulipalin A, has been detected in many species of Alstroemeria and Bomarea Mirb. Alpha-methylene-gamma- butyrolactone. Fingertip allergic contact dermatitisis caused by contact with recently damaged plants and bulbs, and gives rise to a condition known as tulip fingers. The first case reports of allergic contact dermatitis produced by Alstroemeria species appeared early in the 1970s. Gardeners, florists, and housewives are at most risk. Typically, patients are florists who present with red, thickened and split, tender finger tips of both hands Airborne contact dermatitis has also been reported. This may reflect sesquiterpene lactone sensitivity. More unusually, alstroemeria has been observed to cause depigmentation. A florist developed a sense of throat tightness, allergic rhinoconjunctivitis, urticaria, and facial angioedema attributable to exposure to alstroemeria. For most patients, the allergy leads to a change of profession.
20 -Which of the following plant families commonly causes phytophotodermatitis?
A. Rubiaceae
B. Compositae
C. Urticaceae
D. Ranunculaceae
E. Apiaceae
►E
The Apiaceae family (formerly Umbelliferae) includes parsley, celery, parsnip, hogweed, and fennel, all potential causes of phytophotodermatitis.
21 -Crusted scabies is a risk factor for all the follow patients except:
A. HIV
B. Elderly
C. Transplant patients
D. Children
E. Farmers
►E
All the following are risk for developing crusted scabies or Norwegian scabies, which are seen in immuno-compromised hosts except for farmers. Crusted scabies are infested with innumerable mites. The mites can survive for up to a week.
22 -Pineapples contain which of the following proteolytic enzymes?
A. None of these answers are correct
B. All of these answers are correct
C. Bromelin
D. Phorbol esters
E. Ranunculin
►C
Bromelin is a proteolytic enzyme found in pineapples. It is granted access to dermal vessels by calcium oxalate-induced fissures. Phorbol esters are found in plants of the Euphorbiaceae family. Ranunculin is an irritant found in buttercups (Ranunculaceae family).
23- Which disease is transmitted by this insect?
A. Visceral leishmaniasis
B. African sleeping sickness
C. Chagas disease
D. Dracunculiasis
E. Onchocerciasis
►E
The insect depicted is the black fly, Simulium species. The black fly is the vector for onchocerciasis, which is caused by onchocerca volvulus. Clinical manifestation of this disease include atrophy, depigmentation and thickening of the skin. In addition, the infection may cause “river blindess” and onchocercomas, which are nodules containing microfilariae.
24- Lipase is a notable active component of the venom of which of the following spiders?
A. Lycosidae
B. Lactrodectus
C. Hidippus
D. Chiracanthium
E. Loxosceles
►D
The venom of Chiracanthium (sac spiders) contains lipase. The venom of Lycosidae (wolf spiders) is notable for histamine; Lactrodectus (black widow spiders) for alpha lactrotoxin; Hidippus (jumping spiders) for hyaluronidase; and Loxosceles (brown recluse spiders) for sphingomyelinase D.
25- Identify this caterpillar:
A. Hag moth caterpillar
B. Puss caterpillar
C. Greenback caterpillar
D. Saddleback caterpillar
E. Io caterpillar
►D
This is the saddleback caterpillar, as it appears that the caterpillar is wearing a saddle.
26- Necrosis may be seen in which of the following:
A. Allergic contact dermatitis
B. Contact urticaria
C. Dermatographism
D. Irritant contact dermatitis
E. Acute urticaria
►D
Necrosis may be seen in severe irritant reactions. The other reactions do not involve necrosis.
27- Mosquitoes cause yellow fever and dengue. The cutaneous reaction is due to the female inserting her blood tube, injecting irritating salivary secretions that anticoagulate blood. Another name for mosquitoes are:
A. Anopheles
B. Dipetalonema perstans
C. Pulex irritans
D. Ctenocephalides felis
E. Trypanosoma cruzi
►A
The other word for mosquitoes is anopheles that causes malaria. It causes yellow fever and dengue and most mosquitoes prefer black skin, young skin, warm to cool skin and scented skin. They also refer bright colors also.
28- Which of the following statements regarding Theraphosidae is correct?
A. Bites do not generally produce any systemic toxicity
B. These creatures possess urticating hairs that are of dermatologic significance
C. These creatures can cause visual loss by causing a chronic granulomatous reaction (ophthalmia nodosa)
D. All of these statements are correct
E. None of these statements are correct
►D
Theraphosidae (tarantulas) are large, brown to black, hairy spiders frequently found in the southwest. They are of dermatologic importance due to urticating hairs. Tarantula bites generally do not produce any systemic toxicity. The spider releases hairs in the direction of the perceived attacker; hairs can penetrate the skin as deeply as the reticular dermis. If they injure the cornea, they can cause a chronic granulomatous reaction (ophthalmia nodosa) and loss of vision.
29- Identify this insect:
A. Tabanid fly
B. Water flea
C. Tsetse fly
D. Reduviid bug
E. Black fly
►A
The insect indentified is a fly of the Tabanid family, which encompasses horseflies and deerflies. The genus Chrysops of this family is the vector for loiasis. Clinical manifestations of this infection include painful, localized subcutaneous nonpitting edema, calabar swellings and eosinophila. Conjunctival migrations are common.
30- Ananas comosus causes an irritant dermatitis attributed to which irritant?
A. Phorbol esters
B. Capsaicin
C. Thiocyanates
D. Bromelin
E. Ranunculin
►D
Ananas comosus is the pineapple. Pineapples contain the irritants bromelin (a proteolytic enzyme) and calcium oxalate (which causes fissures that grant bromelin access to dermal vessels). Capsaicin is found in chili peppers. Phorbol esters are found in spurges, crotons, poinsettas, and machineel trees. Thiocyanates are found in garlic, mustard, and radishes. Ranunculin is found in buttercups.
31- Which of the following infections is commonly known to occur from contact with infected sheep?
A. Infectious pustular dermatitis
B. Cutaneous anthrax
C. Oculoglandular syndrome of Parinaud
D. Erysipeloid
E. Infectious pustular dermatitis and cutaneous anthrax
►E
Infectious pustular dermatitis is another name for orf, or ecthyma contagiosum. It is transmitted to humans by a parapoxvirus in sheep, goats, and reindeer. Cutaneous anthrax is also called “woolsorter’s disease” and is caused by Bacillus anthracis, a gram -positive rod transmitted from contact with carcasses of infected sheep, cows, goats, and horses. The oculoglandular syndrome of Parinaud is the combination of granulomatous conjunctivitis and preauricular lymphadenopathy seen in cat-scratch disease.
32- Identify this tick:
A. Ixodes dammini
B. Dermacentor andersoni
C. Dermacentor variabilis
D. Amblyomma americanum
E. Rhipicephalus sanguineus
►D
This is Amblyomma americanum which transmits Lyme as well as RMSF.
33- The majority of naturally-occurring cases of anthrax:
A. Are extra-cutaneous
B. Are acquired through ingestion of spores
C. Are oropharyngeal
D. Are pulmonary
E. Are cutaneous
►E
The majority (95%) of naturally-occurring cases of anthrax are of the cutaneous form, acquired from direct contact with the carcasses of dead sheep, cows, goats, and horses. Naturallyoccurring pulmonary, gastrointestinal (acquired by ingestion of spores) and oropharyngeal infection with anthrax is less common.
34- Contact urticaria is a:
A. Type I hypersensitivity
B. Type II hypersensitivity
C. Type III hypersensitivity
D. Type IV hypersensitivity
E. Undetermined hypersensitivity
►A
Contact urticaria is an example of a type I hypersensitivity reaction. The classic example is a latex induced contact urticaria. Type I reactions (immediate hypersensitivity reactions) involve immunoglobulin E (IgE)–mediated release of histamine and other mediators from mast cells and basophils.
35- Ehrlichiosis is classified in two primary forms. These are:
A. Monocytic and granulocytic
B. Endemic and epidemic
C. Intracellular and extracellular
D. Primary and secondary
E. None of these answers are correct
►A
Ehrlichiosis comes in two forms: monocytic, which invades mononuclear WBCs, and granulocytic, in which peripheral PMNs show intracytoplasmic inclusions. Patients present with fever, chills, headache, and myalgias, along with leukopenia, anemia, and thrombocytopenia.
36- A 54 year-old man with psoriatic arthritis on methotrexate and infliximab calls you after he is bitten deeply on the ankle by his daughter’s 2 year-old Chihuahua. He is concerned that his immunocompromised status puts him at risk for infection and potential complications from this bite. You correctly tell him:
A. As long as the dog has been vaccinated, he need not worry about serious infections
B. Capnocytophaga from dog bites can cause sepsis in immunocompromised victims
C. Eikenella corrodens is the most common cause of infection following dog bites
D. Pasteurella multocida infection is frequent after dog bites but not cat bites
E. Rickettsial pox can be seen after dog bites
►B
Local infection and cellulitis is a concern following domesticated animal bites; vaccination may prevent against rabies, but not other infections. Cat bites most frequently result in Pasteurella multocida infections, while dog bites result in Pasteurella canis. However, most bites are polymicrobial with mixed aerobes and anaerobes. Infrequently systemic infections may r esult in brain or lung abscess, endocarditis, or sepsis. Sepsis is more frequent in immunocompromised victims and may be due to Capnocytophaga or Pasteurella.
37- A patient who experiences an allergic contact dermatitis in reaction to an extract from the P inus palustris tree may also be sensitized to:
A. Rosin
B. Mascara
C. Varnish
D. None of these answers are correct
E. All of these answers are correct
►E
Colophony, derived from the Pinus palustris tree, may cross react with rosin, medications, mascara, adhesives, bandages, varnish, wax, paper products, and dental cement.
38- Allergic contact dermatitis is a:
A. Type I hypersensitivity
B. Type II hypersensitivity
C. Type III hypersensitivity
D. Type IV hypersensitivity
E. Undetermined hypersensitivity
►D
Allergic contact dermatitis is an example of a Type 4 hypersensitivity reaction (delayed type hypersensitivity reaction). Type 4 reactions are mediated by T -cells. Other types of hypersensitivity reactions are described below. Type I reactions (immediate hypersensitivity reactions) involve IgE– mediated release of histamine and other mediators from mast cells and basophils. Type II reactions (cytotoxic hypersensitivity reactions) involve immunoglobulin G or immunoglobulin M antibodies bound to cell surface antigens, with subsequent complement fixation. Type III reactions (immune- complex reactions) involve circulating antigen-antibody immune complexes that deposit in postcapillary venules, with subsequent complement fixation.
39- A patient comes to you with complaints of numerous erythematous pruritic papules under her bathing suit after swimming in the ocean. What is the most likely diagnosis?
A. Swimmer”s itch
B. Hot tub folliculitis
C. Seabather”s eruption
D. Hydrozoa contact
E. Nematocyst stings
►C
Sea bather”s eruption is seen after ocean exposure and can be intensely pruritic. It is due to jellyfish larvae (Linuche unguiculata) and can be prevented by rinsing off soon after coming out of the water. Swimmer”s itch is a cercarial dermatitis caused by avian schistosomes which occurs after freshwater exposure. It is usually seen on exposed areas. Portuguese man of war (hydrozoa) stings can lead to hemorrhagic lesions with vesiculations.
40- Which of the following statements regarding Megalopyge opercularis is correct?
A. Are also called “bed bugs” by lay people
B. Contact with this creature often causes immediate pain, urticaria, and erythematous papules or purpura in a tram-track pattern
C. Bites are usually asymptomatic, initially, but then form linear purpuric macules
D. These creatures can be vectors of many diseases from typhus to plague
E. These creatures, found in Hawaii, are nocturnal carnivores that produce painful wounds by discharging venom
►B
Megalopyge opercularis (puss caterpillar) is one of the most widespread causes of caterpillar dermatitis. Contact with this creature often causes immediate pain, urticaria, and erythematous papules or purpura in a tram-track pattern. Bites of Cimicidae (bedbugs) are usually asymptomatic, initially, but then form linear purpuric macules. Fleas can be vectors of many diseases from typhus to plague. Chilopoda (centipedes) are nocturnal carnivores that produce painful wounds by discharging venom. Scolopendra is a species of centipede found in Hawaii.
41- Which of the following vectors transmits Borrelia duttonii?
A. Ixodes pacificus
B. Rhipicephalus sanguineus
C. Ornithodoros moubata
D. Amblyomma americanum
E. none of the above
c
►C
Borrelia duttonii is a pathogenic organism of relapsing fever. It is transmitted by Ornithodoros moubata. Ixodes pacificus is one of the vectors of Lyme Borreliosis. Rhipicephalus sanguineus is a vector of Ehrlichiosis. Amblyomma americanum is a vector of Lyme Borreliosis and Rocky Mountain Spotted Fever.
42- Which of the following is not a hallmark of allergic contact dermatitis?
A. Eosinophils
B. CD4+ Lymphocytes
C. Langerhans cells
D. Neutrophils
E. Vesicles
c
►D
Langerhans cells present the antigens to CD4+ lymphocytes in the dermis and after traveling through lymphatics to regional lymph nodes. Eosinophils may also be present. Neutrophils are not characteristic of this reaction.
43- A butcher presents with numerous verrucous papules of the hands and fingers. Based on her occupation, you consider a diagnosis of infection with which HPV types?
A. HPV 16 and 18
B. HPV 1 and 2
C. HPV 2 and 7
D. HPV 6 and 8
E. HPV is not associated with this condition
►C
Meat, fish, and poultry handlers often suffer from hand and finger verrucae, usually caused by human papilloma virus types 2 and 7.
44- Solenopsin D is a:
A. Hemolytic factor
B. Phospholipase
C. Piperdine derivative
D. Histamine-releaser
E. Hemolytic factor, piperdine derivative, histamine-releaser
►E
Solenopsin D is a venom which is a hemolytic factor, a piperidine derative and leads to histamine release. The venom from honeybeeds contains phospholipase A .
45- An iguana is a pet that can harbor this organism that has been known to cause cellulitis with severe systemic manifestations. The organism is most likely:
A. Serratia marcescens
B. Salmonella
C. Cheyletiella
D. Dermayssus
E. Glyciphagus
►A
An iguana is an inexpensive pet that can carry herpes, Serratia marcescens and salmonella. Serratia marcescens causes severe cellulitis in humans.
46- Which of the following mites is also known as the chigger and often causes intense pruritus on the ankles, legs, or belt line?
A. Ornithonyssus
B. Glyciphagus
C. Demodex
D. Allodermanyssus sanguineus
E. Trombicula alfreddugesi
►E
Trombicula alfreddugesi (chigger mite, harvest mites) frequently causes intense pruritus on the ankles, legs, or belt line. Contact occurs during summer and fall. In sensitized individuals, papular urticaria, vesiculation, or a granulomatous reaction with fever and lymphadenopathy may occur. Allodermanyssus sanguineus (house mouse mite) is the vector of rickettsial pox. Demodex folliculorum is a mite that can live within the sebaceous glands of hair follicles and may be important in some subsets of patients with acne rosacea, as well as patients with HIV infection and folliculitis. Glyciphagus (cheese mite) is the cause of grocer’s itch. Ornithonyssus (fowl mite) can carry Western equine encephalitis.
47- Flying squirrels can carry many infections, including which of the following?
A. Epidemic typhus
B. Staphlyococcus sp
C. Toxoplasma gondii
D. none of these infections are correct
E. all of these infections are correct
►E
Flying squirrels can carry many infections, including Toxoplasma gondii, Staphylococcus sp., and Rickettsia prowazekii (via the body lous, causing epidemic typhus).
48 -A patient has an necrotic lesions with extensive gangrene. In children, it can cause fever, chills, vomiting, joint pain and hematuria with shock and death. The spider has a violin-shaped marking on the abdomen and is therefore the:
A. Loxosceles
B. Lactrodectus
C. Lycosidae
D. Hidippus
E. Chiracanthium
►A
This patient has a bit from the brown recluse spider also known as the Loxosceles. The venom content is the sphingomyelinase-D. Treatments have been disappointing such as dapsone, steroids, aspirin, and anti-venom.
49 -Plants from the family Moraceae include which of the following?
A. Ficus carica
B. Fennel
C. Burning bush
D. All of these answers are correct
E. None of these answers are correct
►A
Ficus carica (fig tree) is a member of the family Moraceae and a cause of phytophotodermatitis. Burning bush is a member of the family Rutaceae. Fennel is a member of the family Apiaceae.
50- Snake bite antivenin is derived from:
A. Human antibody
B. Mouse antibody
C. Antigen extracted directly from the attacking snake
D. Horse antibody
E. Pooled IVIg
►D
Following envenomation, antivenins are derived from horses.
51- Onions and chives:
A. Contain diallyl disulfide
B. Are members of the family Anacardiacea
C. Contain pentadecylcatechol
D. Are members of the same family as Gingko
E. Cross-react with artichoke in sensitized patients
►A
Onions, garlic, and chive are members of the family Alliaceae and contain diallyl disulfide (also allylpropyl disulfide, allicin).
52- Erysipeloid is an infection that causes a sharply marginated and polygonal patches of bluish erythema. Patients usually develop a solitary violaceous and tender nodule that vesiculates. The most likely source of this infection is:
A. Pigs
B. Deer
C. Plants
D. Tress
E. Tics
►A
Erysipeloid is caused by a gram positive rod called Erysipelothrix insidiosa or rhusiopathiae. This type of bacteria is found in fish, birds, mammals, and shellfish. It usually affects people who work with these animals (farmers, butchers, fish handlers, and veterinarians can be affected). Treatment is with erythromycin or penicillin.
53 -The vector for Babesia microti is also a vector for:
A. None of these answers are correct
B. All of these answers are correct
C. Francisella tularensis
D. Rickettsia rickettsii
E. Borrelia burgdorferi
►E
The vector for Babesia microti (pathogenic organism of babesiosis), is Ixodes dammini, which is also a vector for Borrelia burgdorferi, the pathogenic organism of Lyme borreliosis. Francisella tularensis (the pathogenic organism of tularemia) is transmitted by Dermacentor andersoni and Dermacentor variabilis. Rickettsia rickettsii (the pathogenic organism of Rocky Mountain Spotted Fever) is transmitted by Dermacentor andersoni, Dermacentor variabilis, and Amblyomma americanum.
-Which of the following infections is caused by a gram-positive rod?
A. Erysipeloid of Rosenbach
B. Brucellosis
C. Cat-scratch disease
D. Glanders
E. Milker’s nodule
►A
Erysipeloid of Rosenbach is an infection with Erysipelothrix insidiosa or Erysipelothrix rhusiopathiae, gram-positive rods. Brucellosis is caused by infection with Brucellae (gramnegative rod). Cat-scratch disease is caused by infection with Bartonella henselae, a gramnegative rod. Glanders is caused by infection with Burkholderia Mallei, a gram-negative rod. Milker’s nodule is caused by the paravaccinia viurs, a parapoxvirus related to the orf virus.
55- Identify this insect:
A. Phlebotomous sandfly
B. Tsetse fly
C. Reduviid bug
D. Water flea
E. Mango fly
►C
This a picture of the reduviid bug, also called the kissing bug or assassin bug. It is the vector for American Trypanosomiasis (Chagas disease), which is caused by Trypanosoma cruzii. The reduviid bug prefers to bite at mucocutaneous junctions.
56- A 21 year old college student returning back to school from a spring break trip presents with 12 days of headache, fever, and a skin lesion with annular erythema on her upper back measuring 15 cm in diameter. This multi-system disease is most likely caused by?
A. Treponema pallidum
B. Borrelia burgdorferi
C. Staphylococcus aureus
D. Francisella tularensis
E. Pseudomonas aeruginosa
►B
Lyme disease is a multisystem disease caused by Borrelia burgdorferi that is transmitted to humans by ticks of the genus Ixodes. Patients present with variable constitutional symptoms including HA, fever, malaise, and arthralgias. 75% of patients develop erythema chronicum migrans that begin as an erythematous papule that can progress to an annular erythema reaching 20 cm or more in size.
57- A 47 year old park ranger developed a diffuse, erythematous, eczematous eruption after fighting a forest fire. What is the most likely allergen causing this airborn contact dermatitis?
A. Diallyl disulfide
B. Pyrethrins
C. Alphamethylene
D. Psoralen
E. D-usnic acid
►E
Lichen causes airborne allergic contact dermatitis in lumberjacks, forest workers, and people exposed to firewood, funeral wreaths, and masculine fragrances. The primary allergen is d-usnic acid.
58 -Insects from the species pictured:
A. Transmit malaria
B. Trasmit yellow fever
C. Transmit dengue fever
D. Transmit malaria and yellow fever
E. Trasmit yellow fever and dengue fever
►E
The insect pictured is an Aedes mosquito. Aedes transmits yellow fever and dengue fever. Anopheles mosquitoes transmit malaria.
59- When doing patch testing for compositae sensitivity, which of the following substances is used?
A. Colophony
B. Pentadecacatechols
C. Rhus
D. Sesquiterpene lactone mix
E. Tuliposide A
►D
Colophony cross reacts with turpentine resin, hairpiece adhesive, mascara, dental cement and others. Pentadecacatechols are in the rhus family and are found in poision ivy, oak and sumac in addition to cross reacting with mango and cashew. Tuliposide A is found in Peruvian lily (alstomeria), and tulip.
60- Poison sumac is:
A. A member of the Toxicodendron genus
B. A source of tuliposide A
C. The common name for Myroxylon balsamum
D. The common name for Pinus palustris
E. A source of colophony
►A
Poison ivy, oak, and sumac are members of the Anacardiacea family, Toxicodendron genus. Alstromeria (Peruvian lily) is the source of tuliposide A. Myroxylon balsamum is the source of Balsam of Peru. The Pinus palustris tree is the source of colophony.
64- Match the photo to the plant identified:
A. Alliaceae
B. Primulaceae
C. Anacardiacea
D. Compositae
E. Alstromeria
►E
Alstromeria is pictured.
67 -This spider can cause acutely painful and may swell but do not cause necrosis. The venom contains neurotoxins and can cause vomiting, violent cramps, paralysis, and spasms. The most likely spider is:
A. Lactrodectus
B. Loxosceles
C. Lycosidae
D. Phidippus
E. Cheiracanthium
►A
Lactrodectus is the black widow spider. The patient can within hours develop chills, vomiting, violent cramps, paralysis, spas,s and symptoms mimicking an acute abdomen. An antivenin may be helpful up to 90 hours after the bite.
72 -What is the initial treatment of choice for this dermatitis?
A. Observation
B. 5% acetic acid
C. Topical petrolatum jelly
D. Topical antibiotics
E. Warm compresses
►B
The linear appearance of the dermatitis is typical of jellyfish stings. To prevent further nematocyte activation, 5% acetic acids should be applied for 15-30 minutes. Papain found in meat tenderizers or
70% isopropyl alcohol may also be applied. Warm compresses are contraindicated as they may increase systemic absorption of the venom.
75-Match the photo to the plant identified:
A. Poison ivy
B. Gingko
C. Poison oak
D. Mango leaves
E. Poison sumac
►C
Poison oak is identified by leaf shape - irregular lobing and varied leaf size.
77 -Identify this plant:
A. Alstromeria
B. Toxicodentron
C. Myroxylon balsamum
D. Ragweed
E. Primrose
►E
This is primrose (primulaceae) a cause of allergic contact dermatitis.
82- The hobo spider is the leading cause to necrotic arachnidism in the Pacific Northwest. The spider is larger, with a herringbone-striped pattern on the abdomen and the bite can be painless but develop erythema and numbness. This spider is also known as:
A. Tegenaria agrestis
B. Loxosceles reclusa
C. Lactrodectus mactans
D. Peucetia viridans
E. Phidippus formosus
►A
The other name is Tegenaria agrestis. The necrotic eschar will develop with slow healing. Systemic reactions can consist of headache, visual disturbances, and hemodynamic changes.
c
84- Match the photo to the plant identified:
A. Poison ivy
B. Gingko
C. Poison oak
D. Mango leaves
E. Poison sumac
►E
Poison sumac leaves grow in groupings of 7-13 with a single leaf at the tip.
86- When bitten with the spider in the photograph, the active agent in the venom is:
A. Alpha lactrotoxin
B. Histamine
C. Hyaluronidase
D. Lipase
E. Sphingomyelinase-D
►A
This is a black widow spider which can be identified by its shiny black body with characteristic red hourglass marking on the abdomen.
106- This organism is:
A. Pediculus humanus
B. Pulex irritans
C. Chigoe flea
D. Pediculus capitis
E. Pthirus pubis
►E
This is a crab louse. It is shorter and wider than the head and body louse. Note the crab -like claws.
This snake, the coral snake, is a member of what family?
A. Crotalidae
B. Lepidoptera
C. Elapidae
D. Theraphosidae
E. Apiaceae
►C
The Crotalidae family includes rattlesnakes and copperheads. Lepidoptera are caterpillars. Theraphosidae is the scientific name for tarantulas. Apiaceae (Umbelliferae) is a plant family which includes parsley, celery and fennel. Elapidae is the correct family of snakes, including coral snakes.
111- Which disease is transmitted by this insect?
A. African sleeping sickness
B. Chagas disease
C. Dracunculiasis
D. Visceral leishmaniasis
E. Onchocerciasis
►B
This a picture of the reduviid bug, also called the kissing bug or assassin bug. It is the vector for American Trypanosomiasis (Chagas disease), which is caused by Trypanosoma cruzii. The reduviid bug prefers to bite at mucocutaneous junctions.
113- Match the photo to the plant identified:
A. Alliaceae
B. Primulaceae
C. Toxicodendron
D. Compositae
E. Alstromeria
►D
This is ragweed, a member of the compositae (or asteraceae) family.
114- Name this creature:
A. Demodex folliculorum
B. Ornithonyssus sylviarum
C. Pthirus pubis
D. Pediculus capitis
E. Pediculus humans corporis
►D
This is the head louse (Pediculus Humans Capitis) has a narrow body. The body louse or Pediculus humanus var. corporis has an elongated abdominal region . The pubic louse (pthirus pubis) is shorter, and squatter.
115 -Which chemical is present in large quantities of this arachnid’s venom?
A. Sphingomyelinase D
B. Alpha lactrotoxin
C. Histamine
D. Hyaluronidase
E. Lipase
►C
The spider shown is the Wolf spider (Lycosidae). This Australian spider’s bites contains large amounts of histamine. Bites are painful with edema, erythema and subsequent lymphangitis.
127 -This patient complains of intense itching at this site. KOH examination is negative. She denies any recent travel, however does take her 2 year old to the local playground where there is a sandbox. Which of the following is appropriate?
A. Obviously this is dermatophyte despite a negative KOH. Treat with topical antifungals
B. Inform the patient she is contagious and should isolate herself from her children
C. Slowly extract the organism
D. Give her clobetasol ointment
E. Treat with po ivermectin
►E
This is hookworm, or cutaneous larva migrans; systemic ivermectin or topical thiobendazole would be appropriate treatments. The causative organism is the larvae of Ancylostoma braziliensis or A. canium.
129 -This is a:
A. Moth caterpillar
B. Puss caterpillar
C. Woolybear caterpillar
D. Brownbear caterpillar
E. Furrybear caterpillar
►C
This is a woolybear caterpillar.
132- A meat handler has extensive verrucous papules that are cauliflower like lesions on the dorsal, palmar and periungual aspect of the hand. The HPV subtype that causes butcher’s wart is:
A. HPV 2, 7
B. HPV 3, 5
C. HPV 7, 9
D. HPV 1, 4
E. HPV 11, 13
►A
Butcher’s wart is caused by HPV 2, 7. It is from meat and poultry handlers. It is not caused by the animal papillomavirus type.
135- This tick transmits:
A. Lyme
B. Relapsing fever
C. Rocky mountain spotted fever
D. Erlichiosis
E. Babesiosis
►C
This is Dermacentor variabilis which transmits Rocky Mountain Spotted Fever as well as Tularemia.
144 -The reaction caused by this plant is mediated by:
A. Langerhans cells
B. Eosinophils
C. IgE
D. Mast cells
E. Histamine
►A
This is ragweed, which causes allergic contact dermatitis. Mast cells, IgE and histamine are characteristic of contact urticaria. Allergic contact dermatitis is caused by langerhans cells presenting antigen to CD4+ lymphocytes leading to a cell-mediated delayed hypersentitivity reaction.
149- This creature can do the following EXCEPT:
A. Be used as a natural control for the tick population
B. Cause anaphylaxis
C. Transmit Yersinia pestis
D. Cause a painful sting
E. Build large characteristic mounds
►C
This is a fire ant. In some parts of the world, they are used as a natural tick control as they are scavengers and consumers of tick eggs. They can cause anaphylaxis in an allergic person. They do not transmit disease. The mounds are characteristic in appearance.
c
151- Allergic contact dermatitis caused by the pictured plant is mediated by which sensitizer?
A. Diallyl sulfide
B. Sesquiterpene lactones
C. Colophony
D. Primin
E. Tuliposide A
Correct choice: D. Primin
Explanation: The pictured plant is the primrose; allergic contact dermatitis to this plant is mediated by primin.
Diallyl sulfide is found in garlic. Sesquiterpene lactones are found in the Compositae family. Colophony is found in Pinus palustris tree. Tuliposide A is found in the Peruvian lily.
