Table of Content


Autumn 2019, Vol. 27 No. 3

Hong Kong J. Dermatol. Venereol. (2019) 27, 148

Dermato-venereological Quiz

Dermato-venereological Quiz

HF Cheng 鄭學輝


A 30-year-old attendee presented with a few months history of lesions over his axillary hair (Figures 1a and 1b). The condition was entirely asymptomatic and there was no significant past medical history.

Figure 1a The appearance of the hairs over the left armpit.

Figure 1b A close-up view of the armpit hairs, showing waxy yellowish materials coating the surface of the hair shafts.


  1. What are your differential diagnoses?
  2. What are the investigations?
  3. What is the definitive diagnosis?
  4. What are the recognised predisposing factors for this clinical condition?
  5. What is the causative agent? What other skin conditions can it cause?
  6. What are the treatment options?
  7. What is the prognosis?