AKT

1. A 52 year-old woman presents with an itchy rash on both wrists for the last three months. (See Figure 1) What is the SINGLE MOST likely diagnosis in this patient? Select ONE option only.

A. Contact dermatitis
B. Lichen planus
C. Pityriasis rosea
D. Psoriasis
E. Tinea corporis

Answer: B

This picture demonstrates the typical appearance of shiny, flat-topped, violaceous (purple/mauve colour) polygonal papules on the flexural aspects of the wrists which occur in lichen planus. There may be a fine white lace-like pattern on the surface which are called Wickham’s striae. Mucosal membranes including the genitalia may be affected, and treatment usually involves potent topical steroids. The aetiology is thought to be auto-immune.Pityriasis rosea typically presents with a scaly rash that is normally flat or only slightly raised. It is more common in children and young adults and usually affects the trunk predominantly. Human herpes viruses 6 and 7 may be implicated in the aetiology.Chronic extensor plaque psoriasis typically affects the elbow, knees, umbilicus, scalp and natal cleft. Other less common variants of psoriasis can occur, including a flexural type.Tinea corporis has typically a more scaly and annular appearance would be expected with a fungal infection.