Werner syndrome is a rare, autosomal, recessive condition that is frequently studied as a model of some

1555ouabain binding capacity of cells from patients with essential hypertension can increase during incubation in the absence of the inhibitor. We do not suggest that the serum inhibitor is solely responsible for the disorder of leucocyte transport of cations in essential hypertension. Our study does not exclude a deficiency of other, ouabain resistant, cation transport pumps in the leucocyte.Our findings show, however, that the leucocyte is a useful model for studying in vitro the defects of transmembrane cation transport in essential hypertension.We are grateful for the advice of the late Dr R P S Edmondson of the department of renal medicine, Singapore General Hospital. We thank Ms S B Yeo, Ms C S Hay, and Abstract Examination of180 patients with cutaneous malignant melanoma and 197 control patients in a case-control study showed that the risk of melanoma is strongly related to numbers of benign melanocytic naevi (moles). Some unusual features of naevi-a diameter exceeding 7 mm, colour variation, and irregular lateral outline-also showed a strong association with the risk of melanoma, but the relation of numbers of naevi to risk was present even in the group of.patients whose naevi had none of these unusual features. Biopsy of clinically atypical naevi from several of the patients at highest risk generally did not show University of Glasgow A J SWERDLOW, PHD, AMFcM, senior lecturer, department of community medicine J ENGLISH, As, MRcP, registrar, department of dermatology R M MAcKIE, FRSE, FRCPATH, professor, department of dermatology J CLARK, Bsc, research assistant, department of community medicine

Metastatic cutaneous Crohn's disease, in which noncaseating granulomatous infiltration of the skin occurs at sites separated from the gastrointestinal tract by normal tissue, is the least common dermatological manifestation of Crohn's disease. We report the case of an 18-year-old man who developed very widespread metastatic cutaneous Crohn's disease 2 years after he had first developed mild oral and anal lesions. His gastrointestinal symptoms had been satisfactorily controlled for 18 months with sulphasalazine alone prior to his developing skin lesions. The cutaneous lesions responded rapidly to oral prednisolone which was tailed off over 5 months and then withdrawn. He relapsed 6 months later and now requires a low dose of oral prednisolone to control the skin lesions. The only complication of this therapy has been exacerbation of mild acne vulgaris.

Ninety-four renal allograft recipients receiving cyclosporin A (CsA) immunosuppression for up to 4 years were examined for the presence of viral warts, keratoses, and skin cancers. They were compared with a group of 68 recipients on azathioprine who had been matched for duration of immunosuppression and other factors that might influence the occurrence of these lesions. No difference in prevalence of these tumours was found. Viral, bacterial, and fungal infections and other disorders of the skin related to immunosuppression were also noted. Apart from hypertrichosis, which occurred more frequently in the CsA group, no differences were observed. In view of the importance of duration of immunosuppression, the relative effects on the skin of the two drugs will not become apparent until CsA has been in general use for a much longer period of time. In the early stages, however, there appear to be no differences in the dermatological side-effects between CsA- and azathioprine-treated patients.

In a study of risk factors for the development of melanocytic naevi in relation to the pathogenesis of malignant melanoma 197 white adults were examined by four dermatologists and naevus counts correlated with several other features. Highly significant associations were found between large numbers ofbanal acquired melanocytic naevi and the ability to tan easily without burning (skin types 3 and 4; relative risk 4.6), brown or hazel eyes (relative risk 3*5), green or grey eyes (relative risk 3.5), and brown or black hair (relative risk 3.7). No significant associations with numbers This is the first study to find any relation between melanocytic naevi and phenotypic factors in a white population.