Dermatology

Question 1

Which bacteria most commonly infects patients with atopic dermatitis? Which virus?
.

Answer 1

S. aureus most commonly infects patients with atopic dermatitis. Eczema herpeticum is caused by HSV and can cause disseminated infection

Question 2

What is the clinical presentation of seborrhea?

Answer 2

Seborrhea causes yellow or greasy scale overlying erythematous patches or plaques. It commonly affects the scalp, eyebrows, paranasal area, and external auditory canals, although the chest, axilla, and groin areas can also be affected.

Question 3

What is the clinical presentation of intertrigo?

Answer 3

Intertrigo is an irritant dermatitis found in macerated skin folds. It presents with tender, brightly erythematous, moist patches.

Question 4

Allergic contact dermatitis is an example of which type of hypersensitivity reaction?

Answer 4

Allergic contact dermatitis is caused by type 4 delayed-type hypersensitivity reaction.

Question 5

How do you distinguish rosacea from acne vulgaris?

Answer 5

Unlike acne vulgaris, rosacea has telangiectasias without comedones.

Question 6

What are the serious side effects of isotretinoin?

Answer 6

Isotretinoin is severely teratogenic. It is also associated with pseudotumor cerebri.

Question 7

Which inflammatory scarring disease affects the axilla, groin, and perianal areas?

Answer 7

Hidradenitis suppurativa causes inflammatory scarring of the axilla, groin, and perianal areas.

Question 8

Which finding on the buccal mucosa can be seen with measles? Describe and name the finding.

Answer 8

Koplik spots are white papules in the buccal mucosa surrounded by an erythematous border. They usually precede the skin lesions by several days.

Question 9

Which viral infection causes hairy leukoplakia?

Answer 9

Oral hairy leukoplakia is caused by Epstein Barr virus.

Question 10

A beefy red tongue is seen with which underlying disease states?

Answer 10

A beefy, red tongue (glossitis) is seen in pernicious anemia nad various vitamin B deficiencies. It can also be seen in glucagonomas.

Question 11

If you see macroglossia, which underlying diseases should you consider?

Answer 11

Macroglossia is associated with myeloma, primary amyloidosis, lymphoma, hemangioma, acromegaly, hypothyroidism, angioedema, and Down syndrome.

Question 12

Which adverse cutaneous reactions are associated with phenytoin?

Answer 12

Phenytoin can cause various adverse cutaneous reactions. These include a hypersensitivity syndrome (rash, facial edema, lymphadenopathy, and hepatitis), hypertrophied gums, and hirsutism.

Question 13

What is gadolinium? Which adverse reaction can it have?

.

Answer 13

Gadolinium is used for MRI contrast. It can cause nephrogenic systemic sclerosis in patients with underlying renal insufficiency

Question 14

Which drug class is the most common cause of angioedema?

Answer 14

ACE-inhibitors are the most common cause of angioedema.

Question 15

Nail pitting with onycholysis is a fairly specific finding for which dermatologic disorder?

Answer 15

Nail pitting with onycholysis is fairly specific for psoriasis.

Question 16

Which drugs should be added to the regimen for patients with psoriatic arthritis?

Answer 16

Psoriasis patients with psoriatic arthritis should be treated with immunosuppressants (MTX or cyclosporine) or biologic immunomodulators. The latter include TNF-alpha inhibitors (etanercept, infliximab, adalimumab), IL-12 and IL-23 blocker (ustekinumab (Stelara)), and IL-17A blocker ( secukinumab (Cosentyx) and ixekizumab (Taltz)).

Question 17

Characterize the malar rash of systemic lupus.

Answer 17

The malar rash involves both cheeks and extends across the bridge of the nose, sparing the nasolabial fold. It is erythematous and either flat or slightly edematous. It often worsens with sunlight exposure (photosensitivity).

Question 18

What are the manifestations of limited systemic sclerosis?

Answer 18

Limited systemic sclerosis is formerly called CREST syndrome. It presents with calcinosis cutis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasias.

Question 19

What skin findings are associated with sarcoidosis?

Answer 19

Specific sarcoid skin findings include erythematous papules on the face, granulomatous changes in a scar, plaque-like lesions, and micropapular lesions. Nonspecific sarcoid skin findings include erythema nodosum and Lofgren syndrome. Lupus pernio is is a skin change ranging from violaceous (purple) lesions on the tip of the nose and earlobes.

Question 20

What are the skin manifestations of dermatomyositis?

Answer 20

Dermatomyositis causes heliotrope rash of the eyelids, Gottron’s papules, and mechanic’s hands.

Question 21

Pyoderma granulosum is associated with which systemic illness?

Answer 21

Pyoderma granulosum is most commonly associated with inflammatory bowel disease, but it can also be seen in rheumatoid arthritis and hematologic dyscrasias.

Question 22

Which vitamin deficiency causes a photosensitivity dermatitis?

Answer 22

Niacin deficiency causes a photosensitive dermatitis.

Question 23

What are the dermatologic manifestations of zinc deficiency?

Answer 23

Zinc deficiency causes an irritant eczematoid red rash with a prediliction for periorificial and acral areas.

Question 24

Which vitamin deficiency causes follicular hyperkeratosis?

Answer 24

Vitamin C deficiency is associated with follicular hyperkeratosis.

Question 25

Which 2 organisms can cause impetigo?

Answer 25

Impetigo is caused by S. aureus and streptococcus.

Question 26

How does SSSS differ from TEN?

Answer 26

The skin separation in SSSS is more superficial than the depper separation of TEN.

Question 27

Characterize the lesions of disseminated gonorrhea.

Answer 27

Disseminated gonorrhea causes a few (commonly < 12) hemorrhagic pustules on the extremities.

Question 28

What is the significance of finding a lesion of ecthyma gangrenosum on physical exam?

Answer 28

Ecthyma gangrenosum is seen in pseudomonas septicemia.

Question 29

Which antibiotic is used to treat cat bite?

Answer 29

Cat bite should be treated with amoxicillin/clavulanate to cover Pasteurella.

Question 30

Characterize the rash of erythema migrans.

Answer 30

Erythema migrans is a slowly enlarging, annular, erythematous rash with a clear center.

Question 31

Molluscum contagiosum, if seen in an adult, should raise your suspicion for which immunodeficiency?

Answer 31

Molluscum contagiosum in an adult should raise suspicion for HIV infection.

Question 32

How does the dose of acyclovir differ when the drug is used to treat varicella and herpes simplex infections in the immunocompromised?

Answer 32

The dose of acyclovir to treat varicella is higher than that used to treat HSV.

Question 33

Which tinea infections require oral therapy?

Answer 33

Tinea capitis requires treatment with an oral therapy. Otherwise, oral therapy is used for other dermatophyte infections that fail topical therapy. Tinea unguum involving more than ½ of the distal nail is unlikely to respond to topical therapy.

Question 34

What are the treatments for head lice? Which topical treatment is not pesticide-based?

Answer 34

Head lice are treated with spinosad (85% effective), malathion (> 90% effective), topical ivermectin (~95% effective). Benzyl alcohol lotion 5% (Ulesfia) is a newer treatment that contains no neurotoxic pesticides and is ~75% effective.

Question 35

What is the metastatic potential for BCC?

Answer 35

The metastatic potential of BCCC is < 0.1%.

Question 36

Characterize the skin findings associated with porphyria cutanea tarda?

Answer 36

PCT causes hyperpigmentation, tense blisters in sun-exposed areas, milia, skin fragility, and increased facial hair.

Question 37

Which type of hepatitis is associated with PCT?

Answer 37

PCT is associated with hepatitis C virus infection and resolves with treatment of the hepatitis C.

Question 38

What is the pathognomonic lesion for erythema multiforme? Which virus is often the cause?

Answer 38

Erythema multiforme causes “target” lesions that frequently affect the palms and soles and mucus membranes.

Question 39

Dermatitis herpetiformis is associated with which GI disorder?

Answer 39

Dermatitis herpetiformis is associated with celiac disease.

Question 40

In which age group does nummular eczema occur? How is it treated?
.

Answer 40

Nummular eczema typically occurs in the elderly and have no pathologic significance

Question 41

Which skin disorder is characterized by a “Christmas tree” pattern and a herald patch?

Answer 41

Pityriasis rosea is associated with a herald patch followed by a “christmas tree” pattern.

Question 42

What skin finding might you see with a polyglandular autoimmune deficiency syndrome?

Answer 42

Vitiligo should make one suspect a polyglandular autoimmune deficiency syndrome.

Question 43

Hyperpigmented areas of the axilla are associated with which disease states?

Answer 43

Acanthosis nigricans is associated with insulin resistance, diabetes, GI cancer, and several autoimmune problems. Overuse of niacin can also cause acanthosis nigricans.

Question 44

Which diseases are on the short list of causes of black lesions?

Answer 44

Black lesions can be caused by rhinocerebral mucomycosis, anthrax, ecthyma gangrenosum, emboli to distal extremities, melanoma, lentigo, pigmented BCC, warfarin skin necrosis, pigmented seborrheic keratoses, and necrotic spider bite.

Question 45

What is the significance of eruptive xanthomas?

Answer 45

Eruptive xanthomas are caused by severe hypertriglyceridemia.

Question 46

What is the significance of dark atrophic macules in a diabetic?

Answer 46

Diabetic dermopathy is dark, atrophic macules on the shins. They have no clinical significance.