Sebum excretion and acne grades were measured in 20 pairs each of identical and non-identical like-sex twins. The identical twins had virtually identical rates of sebum excretion (P greater than 0.05), but they had a significantly different degree of acne severity (P less than 0.01). The non-identical twins had significantly different sebum excretion rates (P less than 0.01) and acne grades (P less than 0.01). These findings suggest that sebum excretion is under genetic control and the development of clinical lesions is modified by environmental factors.

Four hundred and sixty-two patients suffering from primary irritant hand dermatitis were sent postal questionnaires after 1-16 years regarding the outcome of their dermatitis. Two hundred and thirteen patients replied (a compliance rate of 46%). Of the 213 replies 188 were accepted for analysis, of whom only 58 (30.8%) had complete remission of their dermatitis, whilst 130 patients (69.2%) had continuous, or intermittent disease. Of sixty-four patients who changed their occupation only twenty-one (32.8%) had complete remission of their dermatitis as opposed to thirty-seven (29.8%) of 124 who continued their occupation after the diagnosis of primary irritant hand dermatitis was made. It would appear that the outcome of primary irritant hand dermatitis is not favourable, even after 10 years, and change of occupation has no significant effect.

Dermatofibrosarcoma protuberans is a soft tissue tumor that is often not recognized clinically due to its rarity and variable appearance. Local recurrence is frequent. A wide surgical excision is the treatment of choice.

Fourteen cases of pyoderma gangrenosum were seen over a period of 24 years at the Hull Royal Infirmary Dermatology Department. Several associated conditions were found. Seven cases were associated with rheumatoid arthritis of which five were sero-positive, including one with Felty's syndrome. One case was associated with both ulcerative colitis and psoriasis; one with polycythemia rubra vera; two patients had diverticular disease including one who also had rheumatoid arthritis; one had positive syphilis serology. In three cases there was no significant associated disease identified. Ten out of the fourteen cases were women, indicating a female preponderance by a ratio of about 2F:1M; a figure similar to that stated by Seitzinger. The age of presentation ranged from 30 to 80 years.