Table of Content


Winter 2018, Vol. 26 No. 4

Hong Kong J. Dermatol. Venereol. (2018) 26, 200-201

Dermato-venereological Quiz

Dermato-venereological Quiz

HF Cheng 鄭學輝 and MMT Ng 吳孟婷


A 53-year-old man presented with few month history of an asymptomatic, progressive patch of alopecia. There were no associated symptoms or recent medication use. There was past medical history of epidermoid cyst of the occipital scalp and family history was negative. He did not keep any pets at home. On examination, there was a localised patch of alopecia (4 cm x 3 cm) over the right vertex (Figure 1). Scaling, crusting, and isolated pustules together with tufting of hairs were found within the patch of alopecia (Figure 2). There was a linear scar in the occipital scalp region, from previous surgical excision of the epidermoid cyst. There were no other lesions elsewhere.

Figure 1. Localised patch of alopecia with scaling, crusting and tufting of hairs.

Figure 2. Single patch of alopecia on the vertex. The appearance after de-roofing and microbiological sampling of pustular areas.

Figure 3. Skin biopsy. Haematoxylin & eosin stain magnification x20.

Figure 4. Skin biopsy. Haematoxylin & eosin stain magnification x200.


1. What is the clinical diagnosis and what are the differential diagnoses?

2. What investigations would you like to request?

3. The pathologist found an abundance of plasma cells in the submitted biopsy specimen. Does it sound atypical? What are the necessary precautions?

4. What are the treatment options?