Derm Flashcards
1
Q
Young children, outbreaks common in daycare
- Low fever; mouth and throat pain; vesicular lesions on tongue, buccal mucosa, pharynx or lips
- Nonpruritic skin lesions on hands, feet, buttocks, legs, or arms that are maculopapular, vesicular, or pustular
- mucosal lesions rapidly progress to vesicles that erode and become surrounded by an erythematous halo
A
coxsackie A, hand foot and mouth disease
- nonenveloped, linear ssRNA virus
- MC in summer/early fall
2
Q
proliferation of endothelial cells caused by human herpesvirus-8 (HHV-8) in immunocompromised individuals (AIDS)
- lesions may be cutaneous or visceral
- nearly all patients develop skin lesions, and there are usually multiple lesions on both sides of the body with a symmetrical distribution
- mucous membrane involvement is common
- may be painful, but are not pruritic
A
Kaposi sarcoma
- lungs and GI tract commonly involved
3
Q
nonenveloped, linear ssDNA virus
- “slapped cheek”
- children aged 3-15
- spread via aerosolized respiratory droplets
A
Erythema Infectiosum aka Fifths disease
- caused by parvovirus B19
- low-grade fever, headache, coryza, pharyngitis, nausea, and malaise
- rash starts on face, followed by lacelike rash on the trunk and extremities
4
Q
9-12 month old who develops high (4 day) fever
- followed by a macular rash over the body
A
Roseola
- HHV6, enveloped, linear dsDNA virus
5
Q
what is the other name for measles?
A
Rubeola
- maculopapular rash begins on the face and, over 48 hours, starts to coalesce into patches and plaques that spread caudally to the trunk and extremities, including palms and soles
- transmitted via respiratory droplets
6
Q
fever, exudative pharyngitis, and a scarlatiniform rash
- rash begins initially on the groin and armpits and proceeds to involve the trunk and then the face and extremities
A
Scarlet fever, S. pyogenes
- occurs due to a delayed-type skin reactivity to pyrogenic exotoxins (erythrogenic toxins A, B, C) production from the bacteria
7
Q
dimorphic fungus, caused by landscaping/gardening scratches
- Days to weeks after cutaneous inoculation, a papule develops at the site of inoculation
- primary lesion ulcerates; drainage from the lesion is not grossly purulent and has no odor
- similar lesions occur along lymphatic drainage channels
A
Sporothrix schenckii
8
Q
hot tub folliculitis
A
pseudomonas
- has sweet, grape-like odor when cultured
9
Q
fever, fatigue, body aches, generalized weakness, and a tender erythematous rash
- asymmetric polyneuropathy, can cause both motor and sensory deficits
- associated with HBV infection, usually within the last 6 months
A
PAN
- small-med vessels, particularl renal, cardiac, and GI
10
Q
Young Asian female (< 40 years old), weak upper extremity pulses
A
Takayasu arteritis
11
Q
Older females, unilateral headache, jaw claudication may lead to blindness
- Associated with polymyalgia rheumatica
A
Giant cell arteritis
12
Q
Asian children, conjunctival injection, strawberry tongue, desquamating rash on hands and feet
- aortic dissection, AMI
A
Kawasaki
13
Q
Heavy smokers, autoamputation of digits, Raynaud phenomenon
A
Thromboangiitis Obliterans
Buerger disease
14
Q
p-ANCA (anti-MPO), lungs and kidney affected, similar to Wegener’s, but no nasopharyngeal involvement
A
microscopic polyangiitis
15
Q
c-ANCA (anti-proteinase 3), upper airway, lungs, kidneys, saddle-nose deformity
A
GPA aka Wegener’s
16
Q
P-ANCA, high eosinophilia, mononeuritis multiplex
A
Eosinophilic granulomatosis w/Polyangitis aka Churg-Strauss
- Mononeuritis multiplex is a painful, asymmetrical, asynchronous sensory and motor peripheral neuropathy involving isolated damage to at least 2 separate nerve areas
17
Q
Often after URI or gastroenteritis, 90% occurs in children
- palpable purpura, arthritis/arthralgias, abdominal pain, hematuria
A
IgA Vasculitis (Henoch-Schönlein purpura)
18
Q
what is the medical name for cradle cap?
A
seborrheic dermatitis
- greasy-looking, yellow scales on an erythematous base
- or scaly, oily, salmon-colored plaques
19
Q
what is the medical name of eczema?
A
atopic dermatitis
- causes intense pruritis
- extensor surfaces (in adults)
- dry, scaly, or excoriated erythematous papules
20
Q
rash begins as vesicles and pustules filled with serous fluid that rupture and turn into honey-colored crusted lesions on an erythematous base
A
impetigo
- S. aureus or S. pyogenes
21
Q
superficial, painful blisters that rupture very easily
- autoantibodies against desmosomes
- type II hypersensitivity reaction
A
pemphigus vulgaris
22
Q
tense bullae at the subepidermal or dermal-epidermal junction
- autoantibodies against hemidesmosomes
- do not easily rupture
A
bullous pemphigoid
23
Q
Treatment of tinea corporis?
A
topical antifungals miconazole, clotrimazole, or ketoconazole
24
Q
cutaneous lesions during infancy or early childhood and consists of reddish-orange or yellowish-brown scaly papules, erosions, or petechiae in the groin, intertriginous regions, and scalp
A
langerhans histiocytosis
25
what is the Auspitz sign and when would you see it?
scratching of a silvery psoriasis plaque, leads to microbleeding
26
hyperkeratosis, parakeratosis, acanthosis, rete pegs are elongated, dermal papillae are elongated and hypervascular, mitotic figures above the basement membrane
psoriasis
27
Abundant dermal and epidermal lymphocytes with epidermal necrosis
erythema multiforme
| - Severe cases can transform into Stevens-Johnson syndrome, with necrosis of much of the epidermis and possible death
28
Irregular acanthosis, a band of lymphocytes below the epidermis, and a damaged basal layer
- occurs on the flexor surfaces, especially the wrists
- patients often have white, lace-like lesions in the mouth
lichen planus
29
Septate branching hyphae within the stratum corneum
tinea corporis
30
what causes tinea versicolor/pityriasis versicolor?
| - hypopigmented or hyperpigmented macules and patches normally localized to sebum-rich areas like the chest or back
malassezia furfur
- organism degrades lipids in the skin leading to a production of acids that damage melanocytes and cause the macules and patches of discoloration
- spagetti and meatball on KOH!
31
flesh-colored or erythematous, asymptomatic annular plaques with a firm, ropy border and central clearing. They begin as small lesions and may show slow, centrifugal growth
- usually on dorsal surfaces of hands/feet, wrists/ankles
Granuloma annulare
| - punch bx needed to confirm
32
"dew drops on a rose petal” or small vesicles on an erythematous base that are extremely pruritic
varicella zoster
33
anti-histone Ab?
drug-induced lupus
| - isoniazid, procainamide, hydralazine
34
Anti-microsomal antibodies?
Hashimoto's thyroiditis
35
what is the bad complication of measles?
subacute sclerosing panencephalitis (SSPE)
- often fatal, progressive, degenerative disease of the CNS
- typically an asymptomatic period of 6-15 years between the initial infection and the development of SSPE
36
Congenital albinism is often due to a deficiency in what?
tyrosinase
| - enzyme needed for converting tyrosine to melanin
37
hypopigmentation of the skin due to lack of tyrosine
| - but it is often associated with peculiar body odor and altered brain function including intellectual disability
phenylketonuria
38
IgM antibodies that recognize the Fc portion of IgG
rheumatoid factor
39
porphyria cutanea tarda
?
40
middle aged men
- benign neoplasm of fat cells
- MC benign soft-tissue neoplasm in adults
- round, painless, moveable mass usually found encased in a thin fibrous capsule
- mature univacuolated adipocytes with small nuclei
lipoma
41
most common sarcoma of adulthood. It usually arises in deep soft tissues of the extremities and retroperitoneum
- lipoblasts, with multiple cytoplasmic vacuoles of lipid that scallop the nucleus, and myxoid stroma
liposarcoma
42
benign, soft tissue mass composed of smooth muscle, most commonly found in the uterus
leiomyoma
43
virulence factor of S. pygenes involved in blocking phagocytosis by interfering with C3b binding for opsonization
- antibodies can bind to heart antigens by a process of molecular mimicry and cause rheumatic fever, a type II hypersensitivity reaction
M protein
44
virulence factor of S. pygenes that act as superantigens
- responsible for the development of scarlet fever rash as well as severe clinical manifestations like necrotizing fasciitis and TSS
Spe toxins (SpeA, SpeB, SpeC, SpeF)
45
when do you see pyoderma gangrenosum?
UC
- 2nd MC skin infection in IBD, after erythema nodosum
- *remember the association of UC and PSC!*
46
what does parainfluenza virus cause in young children?
croup
47
what is the tx for Sporothrix schenckii?
itraconazole
48
parasite is transmitted by the black fly, which is found in Africa, Yemen, and parts of South America
- majority of cases are found in the continent of Africa
- second-leading infectious cause of blindness worldwide
onchocerciasis
- aka river blindness
- tx: ivermectin
49
parasite that causes swelling of the skin and presence of subcutaneous worms
- infects the conjunctiva of the eye, in which worms are visible
- rarely leads to blindness
- transmitted by Chrysops flies (including the deer fly, horse fly, and mango fly
```
Loa Loa (loiasis)
- tx: diethylcarbamazine
```
50
spiking fevers, hepatosplenomegaly, and pancytopenia
- transmitted by the sandfly
- commonly found in India
Kala-azar, aka visceral leishmaniasis
| - parasite Leishmania donovani.
51
what is the precursor for SCC of the skin?
```
actinic keratosis ("solar keratosis")
- patch of epidermis where the cells show features of precancer (abnormal nuclei, irregular arrangement) but have not yet invaded
```
52
- neurofibromas anywhere along the path of cutaneous nerves
- irregularly shaped, evenly pigmented, brown macules (café-au-lait spots)
- Lisch nodules
- pheochromocytomas
- optic gliomas
- increased tumor susceptibility
neurofibromatosis type 1 (AD)
| - mutation of tumor-suppressor gene on the long arm of xsome 17
53
inheritance pattern of cystic fibrosis, Tay-Sachs disease, glycogen storage diseases, and phenylketonuria?
AR
54
inheritance pattern of hemophilia A, Hunter syndrome, and G6PD deficiency?
X-linked R
55
deficiency in the essential amino acid tryptophan
| - defects in intestinal absorption and renal tubular reabsorption
Hartnup dz
- Tryptophan is the precursor to nicotinamide and nicotinate — 2 forms of niacin (vitamin B3)
- leads to a deficiency in niacin -> *pellagra*
56
essential AA that is important precursor to tyrosine, necessary for thyroid hormone, dopamine, and melanin formation
- hypopigmentation from decreased melanin
- mental retardation from decreased Dopa and NE
- musty urine
phenylketonuria
- defects in *phenylalanine hydroxylase* lead to an accumulation of phenylalanine and deficiency of tyrosine, thyroid hormone, dopamine, and melanin
- conversion/excretion of phenylalanine -> phenyl ketones = musty urine
57
high fevers, intense headaches, myalgias, and tender lymphadenopathy in axillary, inguinal, and cervical regions
- can also necrose the fingertips
Yersinia pestis
| - effective bioterrorism weapon
58
MPO-ANCA (p-ANCA)?
microscopic polyangiitis (MPA)
- Renal biopsy and pulmonary biopsy are common and most frequently show pauci-immune glomerulonephritis, which is often diffuse and necrotizing with *crescentic formation*
- usually *lacks granulomatous inflammation* in the tissue surrounding the vasculitic small vessels -> DIFFERENT FROM GPA
59
PR3-ANCA (c-ANCA)
granulomatosis w/ polyangiitis (GPA)
| - NOTE: c-ANCA = cytoplasmic staining form
60
- café au lait spots
- axillary freckling
- neurofibromas of peripheral nerves
- pigmented nodules in the iris (Lisch nodules)
neurofibromatosis type 1 (AD)
| - inactivation of the tumor suppressor gene NF1 found on Chromosome 17
61
mutation in HFE gene?
hemochromatosis
62
Gram-negative pleomorphic bacterium (coccobacillus)
- MC presentation in adults is ulceroglandular — a punched out ulcer at the site of inoculation with suppurative lymphadenopathy
- can also contaminate the eyes and lungs
- in central-southern states (pt hunting in Missouri/Arkansas)
tularemia
63
what disease is transmitted by the dermacentor (dog) tick?
rocky mountain spotted fever
64
what is the tx for MRSA?
IV vancomycin
| - binds the D-alanyl-D-alanine portion of the cell wall to block glycopeptide polymerization
65
what is the MC side effect of vancomycin?
Flushing, known as “red man” syndrome
| - can be avoided by a slower infusion rate and co-administration with antihistamines
66
what is the MC side effect of metronidazole?
disulfram rxn
67
what bad side effect is most commonly associated with sulfonamides, penicillins, ethosuximide, lamotrigine, carbamazepine, phenobarbital, phenytoin, and allopurinol
Steven-Johnson syndrome
68
when would you see pigmented hamartomas in the iris called Lisch nodules?
NF type 1
69
proliferations of the cells of the peripheral nerves, especially Schwann cells and fibroblasts
neurofibromas
70
when would you see bilateral acoustic neuromas, which histologically are schwannomas?
neurofibromatosis type 2
| - meningiomas, spinal ependymomas, cataracts, and neuropathies
71
what is a common side effect of tetracycline
photosensitivity
72
what is the quadruple therapy for PUD?
Bismuth subsalicylate
an H2 blocker such as ranitidine
metronidazole
tetracycline
73
what does a negative nitroblue tetrazolium (NBT) staining indicate?
Chronic Granulomatous Disease
- NBT test displays the reactive oxygen species produced by NADPH oxidase; a positive test stains as a blue color indicating the presence of oxidase and subsequent reactive oxygen species
- CGD is caused by a *defect in NADPH oxidase* which impairs oxygen-dependent microbial killing in phagocytes. Therefore, because the oxidase enzyme is lacking in CGD, the NBT test will be negative
74
oval, slightly raised 2-cm to 5-cm plaque or patch with a peripheral scaly appearance
- secondary eruption consists of lesions of the same appearance but smaller and in a tree-like pattern
- usually on trunk and proximal extremities
pitryasis rosacea
| - tx is supportive, and the rash resolves spontaneously within 6-10 weeks
75
diffuse maculopapular rash in a sexually active pt that can involve the trunk, palms, and soles
secondary syphilis
| - rash generally appears 2-6 months after a primary syphilis infection
76
neonate with intrauterine growth restriction, jaundice, hepatosplenomegaly, **periventricular calcifications**
- once born, petechiae/purpura, chorioretinitis, jaundice, seizures, sensorineural hearing loss
CMV
| - blueberry muffin baby
77
triad of eye problems (cataracts), deafness, and congenital heart disease (most often PDA)
congenital rubella
78
baby born with notched teeth and saddle nose?
congenital syphilis
79
why are tetracyclines are not indicated in pregnant or pediatric patients?
they can cause tooth enamel discoloration and growth abnormalities
80
what is preferred tx for lyme dz in pregnancy?
beta-lactam antibiotics (amoxicillin or ceftriaxone), which inhibit transpeptidase
81
bind to the 23S rRNA of the 50S subunit and inhibit protein synthesis by blocking translocation
macrolides
| - erythromycin, azithromycin, and clarithromycin
82
what maternal infection can cause hydrops fetalis?
parvovirus B19
83
premature infant w/significant rhinitis (“snuffles”), hemolytic anemia, thrombocytopenia, a skin rash involving the palms and soles, and hepatomegaly
syphilis
| - sabre shins, saddle nose deformity
84
what is the treatment for scabies?
permethrin
- targets the sodium voltage-gated channels in the parasite leading to death of the insect
can also give ivermectin if not pregnant
- causes an increase in cell membrane permeability with eventual death of the parasite
85
what is the tx for Loa Loa?
diethylcarbamazine (DEC)
- antihelminthic drug that acts by inhibiting arachidonic acid metabolism in filarial microfilaria, which disrupts their membranes and makes them more susceptible to immune attack
86
tinea capitis fungus that produces many large football-shaped macroconidia
Microsporum
87
what is Leser-Trélat a sign of?
| - sudden appearance of multiple pruritic seborrhic keratoses
possible GI malignacy
| - watch out for fatigue (likely iron deficiency anemia) and signs of GI obstruction with constipation.
88
what is acanthosis nigrcans a sign of?
- insulin resistance
| - gastric adenocarcinoma
89
Lyme dz with co-infection causing hemolytic anemia, splenomegaly and jaundice
babesia microti
| - maltese cross under microscope
90
Edema toxin produced by what, is an adenylate cyclase that increases cAMP levels by catalyzing the reaction of ATP to cAMP?
Bacillus anthracis
91
what organism causes overactivation of host cell adenylate cyclase through inhibition of the adenylate cyclase inhibitory Gi alpha subunit protein
Bordetella pertussis
92
what organism ADP-ribosylates the Gs alpha subunit protein, increasing the protein's adenylate cyclase activity and increasing cAMP levels
V. cholera
93
what gram-negative bacillus that is extremely difficult to culture; and is best grown in cysteine-glucose-blood agar?
Francisca tularensis
- similar to yersinia, but has an ulceroglandular lesion that grows, and will rupture, producing a yellow exudate that may turn black
94
neurotoxin can cause muscle pain in the extremities, abdomen, and back
- other sx include cramping, abdominal pain, weakness, headache, nausea, vomiting, and tremor
- bites are very rarely life threatening, and sometimes there is localized diaphoresis in the affected muscle groups
black widow bite
95
what organism is MC associated with burn victims?
pseudomonas
| - tx: aminoglycosides (bind 30s), penicillin
96
spongiosis of the epidermis along with epidermal acanthosis and hyperkeratosis
atopic dermatitis
- flexor surfaces in adults
- extensor surfaces kids <2
97
painful blisters on hands and forearms
- darkened urine
- excess hair growth on the face, forearms, and hands
- hyperpigmentation/hypopigmentation of the hands
- risk factors include alcoholism, hepatitis C, and iron overloaded states
porphyria cutanea tarda (AD)
- deficiency in *uroporphyrinogen III decarboxylase*, an enzyme involved in 5th step of heme synthesis
- results in porphyrins being deposited in the skin causing cutaneous fragility leading to blistering of the hands, forearms, and face
98
what vessels are most at risk for ischemia and necrosis with vasoconstriction caused by epinephrine?
end organs with small capillaries (fingers/toes, ear)
99
dermacentor tick, but saddleback fever?
| - cycles with a fever for 2-3 days followed by absence of fever 2-3 days
colorado tick fever
100
skin thickening w/ systemic sx
- dysphagia, arrhythmias, mild proteinuria and hypertension, and respiratory complications with a restrictive lung defect
diffuse systemic sclerosis
- anti-DNA-topoisomerase (anti-Scl-70) Ab is highly specific for *systemic* sclerosis
- Anticentromere Abs are more characteristic of *limited scleroderma (CREST syndrome)
101
joint pain/swelling, fatigue, muscle weakness, and sclerodactyly
- positive, speckled antinuclear antibody and an anti-U1-RNP antibody
mixed CT disease
102
dysplastic nevus syndrome, is associated with an increased risk of what?
pancreatic cancer
- numerous (> 50) nevi and a first degree family member with melanoma
- likely has familial atypical mole and multiple melanoma syndrome (FAMMM syndrome) aka dysplastic nevus syndrome
103
- eruptive xanthomas result from what?
| - tuberous and planar xanthomas result from what?
- eruptive xanthomas -> hypertriglyceridemia
| - tuberous and planar xanthomas -> hypercholesterolemia
104
what are the most important prognostic indicators for malignant melanoma?
depth and ulceration
105
radiographic findings of a lesion with a lytic center and surrounding ring of sclerosis?
osteomyelitis
106
what drug is used to treat Pasteurella multocida infections resistant to first-line treatment of dog or cat bites
Imipenem/cilastatin
- Imipenem = beta-lactamase–resistant cell wall synthesis inhibitor
- cilastatin = renal dehydropeptidase I inhibitor
- Combining the 2 drugs allows the dose of imipenem to be reduced, thereby decreasing the risk of adverse events
107
what causes scalded skin syndrome?
- presents with a fever and generalized erythematous rash
- rash becomes pustular and bullous, and if a shearing force is applied by a finger, will show sloughing of the upper layers of the epidermis (Nikolsky sign) that heals completely without scarring
caused by the exfoliative toxins produced by Staphylococcus aureus
- typically seen in newborns
108
a superantigen, which binds MHC-II and T-cell receptors outside of the antigenic groove, nonspecifically activating large numbers of T cells to stimulate release of IFN-γ and IL-2
- is responsible for the symptoms of high fever, low blood pressure, rash, and multiple-organ abnormalities
toxic shock syndrome toxin-1 (TSST-1)
109
mutation in nucleotide excision repair?
Xeroderma pigmentosum
- fair skinned baby, severe sun sensitivity
- areas of hypo/hyper-pigmented skin
- can develop skin malignancy as early as 5-6 y/o
110
- chronic hyperkeratosis
- lymphocytic infiltrates at dermo-epidermal junction
- scattered, eosinophillic colloid (civatte) bodies in papillary dermis
- thickened stratum granulosum with *sawtooth rete ridges*
lichen planus
- white lacey appearance
- 6 P's
- on flexoral surfaces of wrists, ankles
