We present two cases of lichen amyloidosus treated with retinoids. A 57-year-old Vietnamese woman has had extensive generalized recalcitrant lichen amyloidosus for 23 years. Treatment with oral etretinate (25 mg/day) for 3 years, and later oral acitretin (10 mg/day) for the past 10 years, has controlled the pruritus and flattened the hyperkeratotic papules. Whenever the acitretin was ceased her symptoms flared within weeks. On each occasion reintroduction of acitretin was effective within 1-2 months. The second case is that of a 51-year-old Australian Aboriginal woman who had a 2-year history of lichen amyloidosus affecting her lower legs. A 2-month course of oral acitretin (25 mg b.d.) produced a marked improvement in both the pruritus and hyperkeratotic papules. She was then lost to follow up for 2 years, during which time her symptoms recurred.

A 47-year-old man presented with an acute, cutaneous eruption of exquisitely painful papules at the operative site 4 weeks after a right tibial osteotomy. Initially this was managed as a postoperative wound infection; however the exacerbation and spread of the cutaneous eruption prompted further investigation. Histopathology and clinical findings were consistent with the development of Sweet's syndrome and resolution was obtained after the initiation of dapsone. We propose that surgery may produce an acute inflammatory response in a similar manner to pathergy reactions, which play an aetiological role in other neutrophilic dermatoses, such as pyoderma gangrenosum. We conclude that there may be greater overlap between these neutrophilic dermatoses than previously appreciated.