Psoriasis

How would you diagnose the rash on her trunk and extremities?

A 54-year-old female with a several year history of psoriasis that is well-controlled on adalimumab presents with a 1-week history of a worsening rash. She had been diagnosed with strep throat and was prescribed amoxicillin a week prior. The rash is itchy and involves the trunk and extremities, but spares palms, soles, and mucous membranes.

psoriasis

How would you diagnose the rash?

A. Psoriasis failure while on adalimumab

B. Guttate psoriasis from streptococcal infection

C. Amoxicillin drug reaction

D. Pityriasis rosea

E. Lichen planus

(Answer and discussion on next page)

AnswerGuttate psoriasis from streptoccal infection

This patient had guttate psoriasis from her streptococcal infection. She was given a 2-month tapering course of methotrexate that resolved the flare. Drug reactions typically do not have this much scale. Both pityriasis rosea and lichen planus would have a different clinical appearance. Psoriasis failure does occur with all the biologics but with the patient’s history, it is not likely here.