Dermatitis DDX

Question 1

ACD/ICD- contact or irritant derm

Answer 1

DP, acute onset, contact hx positive, usually vesicular and oozing

Question 2

Atopic dermatitis

Answer 2

• DP, diffuse dry scaly, allergic hx, fam hx

Question 3

Seborrheic derm-

Answer 3

DP, less itchy, diffuse, scaly, greasy

Question 4

Dyshidrotic Eczema

Answer 4

• DP, deep vesicles, acute, recurring, pruritic

Question 5

Nummular Eczema –

Answer 5

DP, papulovesicular or scaly coin-shaped lesions, biopsy

Question 6

Lichen simplex chronicus

Answer 6

– DP, usually single dry scaly lesion, chronic itch

Question 7

Asteatotic Dermatitis

Answer 7

– DP, dry scaly, common in elderly, worse in winter

Question 8

“Id” reaction –

Answer 8

DP, vesicular, hx of distal primary lesion, linear

Question 9

Polymorphous Light Eruption

Answer 9

– DP, hx of 1st sun exposure 18-24 hours previous

Question 10

Drug-related Eczema

Answer 10

– DP, hx of new drug, herb, chemical exposure

Question 11

Psoriasis-

Answer 11

DP, sharply defined, dry scales, fam hx

Question 12

Pityriasis rosea-

Answer 12

DP, “herald patch”; acute onset, papulosquamous eruption

Question 13

Lichen planus –

Answer 13

DP, 5 P’s, in mouth, Wickham’s striae”, biopsy

Question 14

Tinea capitis, facialis, corporis –

Answer 14

DP, KOH + for fungus

Question 15

Pityriasis versicolor-

Answer 15

DP, fingernail scratch sign, Wood’s lamp, KOH (spaghetti and meatballs)

Question 16

Bacterial infections –

Answer 16

DP, acute vesicular, subacute crusty, lab (culture +)

Question 17

Viral infections –

Answer 17

DP, acute vesicular, lab (culture +)

Question 18

SLE -

Answer 18

DP, fever, malaise, joint pain, lab (ANA, anti smith, double stranded DNA)

Question 19

Secondary syphilis-

Answer 19

DP, lab (RPR, dark field, etc)

Question 20

Erythema migrans-

Answer 20

DP, lab (PCR, Western blot, etc), hx of tick bite

Question 21

Erythema multiforme-

Answer 21

DP, target lesions, following herpes, mycoplasma, drug rx

Question 22

Scabies-

Answer 22

DP, hx (night itching), lab , look like little flea bites