Erythema nodosum (408/1700)

A pt from Africa comes with nodular patch on the shin which is reddish brown. What is the most
probable dx?
a. Lupus vulgaris
b. Erythema nodosum
c. Pyoderma gangrenosum
d. Erythema marginatum
e. Solar keratosis

answer: B

Lofgrens syndrome of Sarcoidosis is more prevalent in Africans
(erythema nodosum, bilateral hilar lymphadenopathy, arthropathy)

other causes include TB which is also prevalent in parts of Africa.

Lupus vulgaris = cutaneous TB
Pyoderma gangrenosum = ulcer associated with RA, IBD, Wegeners
Erythema marginatum = rheumatic fever
solar keratosis = form of skin damage by sun