A 14 year old girl has developed an itchy, scaly patch on her scalp


#1

A 14 year old girl has developed an itchy, scaly patch on her scalp. She had a similar
patch that cleared spontaneously 2 years ago. Her aunt has a similar undiagnosed rash
on the extensor aspects of her elbows and knees. What is the SINGLE most likely
diagnosis?
A. Eczema
B. Fungal infection
C. Impetigo
D. Lichen planus
E. Psoriasis
The fact that she has an itchy, scaly patch on scalp are classic presentation of scalp
psoriasis. Her aunt’s presentations with a similar rash on extensor aspects of her elbow
and knees are suggestive of psoriasis.
Psoriasis
The level of PLAB is rather superficial and it would be unlikely that they would ask you
about types of psoriasis. However, you do need to know how it presents.
Presentation:

  • Itchy, well-demarcated circular-to-oval bright red/pink elevated lesions
    (plaques) with overlying white or silvery scale, distributed symmetrically over
    extensor body surfaces and the scalp
  • Nail changes: pitting, onycholysis
  • Relapses
  • May have a family history