Table of Content


Summer 2019, Vol. 27 No. 2

Hong Kong J. Dermatol. Venereol. (2019) 27, 92-93

Dermato-venereological Quiz

Dermato-venereological Quiz

TH Chan 陳子浩 and KK Jong 莊國坤

A 54-year-old Chinese woman presented with a few discrete skin lesions on the right forearm for one year. The lesions were mildly painful upon touch and there was occasional oozing of blood and discharge from the lesions. She did not have any history of injury or insect bite and she had no constitutional symptoms. She had consulted her general practitioner and had been treated with oral antibiotics with no clinical improvement. She was newly diagnosed to have diabetes mellitus. Her blood tests were normal except for a raised ESR 90mm/hour. Her CXR did not demonstrate any abnormality.

Examination revealed a few erythematous nodules and plaques with scaling and scab on the right forearm (Figures 1-4). An incisional skin biopsy was obtained from the right forearm for histological and microbiological evaluation (Figures 5-7).

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7


  1. Describe the pattern of the arrangement of the lesions?
  2. What additional information is required from the history?
  3. What are the differential diagnoses?
  4. What does the skin biopsy show?
  5. What is the diagnosis?
  6. What is the treatment?