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

HistoryHistoryHistoryHistoryHistory

A 53-year-old man presented with few monthhistory of an asymptomatic, progressive patch ofalopecia. There were no associated symptoms orrecent medication use. There was past medicalhistory of epidermoid cyst of the occipital scalpand family history was negative. He did not keepany pets at home. On examination, there was alocalised patch of alopecia (4 cm x 3 cm) over theright vertex (Figure 1). Scaling, crusting, andisolated pustules together with tufting of hairs werefound within the patch of alopecia (Figure 2). Therewas a linear scar in the occipital scalp region,from previous surgical excision of the epidermoidcyst. There were no other lesions elsewhere.

Dermato-venereological Quiz

HF Cheng and MMT Ng

Social Hygiene Service, Department of Health, HongSocial Hygiene Service, Department of Health, HongSocial Hygiene Service, Department of Health, HongSocial Hygiene Service, Department of Health, HongSocial Hygiene Service, Department of Health, HongKongKongKongKongKong

HF Cheng, MBBS(HK), MRCP(UK)

Histopathology & Cytology, Department of Health,Histopathology & Cytology, Department of Health,Histopathology & Cytology, Department of Health,Histopathology & Cytology, Department of Health,Histopathology & Cytology, Department of Health,Hong KongHong KongHong KongHong KongHong KongMMT Ng, FRCPA, FHKAM(Pathology)

Correspondence to: Dr. HF Cheng

Social Hygiene Service, Sai Ying Pun Dermatological Clinic,3/F, Sai Ying Pun Jockey Club Polyclinic, 134 Queen's RoadWest, Sai Ying Pun, Hong Kong

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

Figure 2.Figure 2.Figure 2.Figure 2.Figure 2. Single patch of alopecia on the vertex. Theappearance after de-roofing and microbiologicalsampling of pustular areas.

Dermato-venereological quiz 201

Figure 3.Figure 3.Figure 3.Figure 3.Figure 3. Skin biopsy. Haematoxylin & eosin stainmagnification x20.

Figure 4.Figure 4.Figure 4.Figure 4.Figure 4. Skin biopsy. Haematoxylin & eosin stainmagnification x200.

QuestionsQuestionsQuestionsQuestionsQuestions

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

2. What investigations would you like to request?3. The pathologist found an abundance of plasma

cells in the submitted biopsy specimen. Does itsound atypical? What are the necessaryprecautions?

4. What are the treatment options? (Answers on page 209)