Answer to last month's Clinical Quiz

Question:
This middle-aged woman presented with pruritic excoriated skin lesions over the limbs and the trunk for several years. The middle back was however relatively spared. The lesions were refractory to various treatments including potent topical steroids and oral antihistamines. She did not have any history of psychiatric disease but was quite tense and neurotic during the consultation.

Answer:
D. Prurigo nodularis

Prurigo nodularis is a psychocutaneous disorder of unknown aetiology, aggravated by compulsive and habitual scratching. It usually presents with multiple intensely pruritic excoriated pigmented nodules over limbs and trunk, especially at the extensor aspects of distal limbs. It may be associated with chronic eczema or arise de novo. The diagnosis may be confused with hypertrophic lichen planus, especially when the lesions occur on the lower limbs. The natural course is usually protracted and the management is very difficult. Treatments consist of topical or intralesional steroid and oral sedative antihistamines, but the result is usually unsatisfactory. Psychological assessment is necessary and a minor tranquilliser may be useful, as emotional stress is often a contributing factor. In severe and refractory cases, thalidomide or phototherapy may help.