Differentiating Psoriasis From Seborrheic Dermatitis (Seborrhoeic Dermatitis) (For Professionals)

• This is particularly useful when the diagnosis is not obvious from clinical examination* (nails, extensor surfaces (elbows), folds on the face):

1. Psoriasis lesions appear reddish
2. Seborrheic Dermatitis (Seborrhoeic Dermatitis) lesions  appear yellowish

*It is typical to have this problem when the lesions are located on the scalp only

• Use a dermatoscope and look at the vessels in the lesions:

1. In psoriasis, vessels appear as twisted loops
2. In seborrheic dermatitis, vessels appear as coiled loops
3. Practically speaking, psoriasis lesions show regular nests of vessels (somewhat like clear cell acanthomas), whereas in seborrheic dermatitis this pattern is not seen, and sometimes, no vessels are seen.

Source of Information:

2012 (09) – 21st Annual Congress of the EADV (European Academy of Dermatology and Venerology) – Prague (Praha), Czech Republic (česká republika)

2013 (03) – Micali G. Dermoscopy beyond Pigmented lesions. 71st Annual Meeting of the AAD (American Academy of Dermatology) – Miami, Florida, United States of America (USA)

Source of information: here