Background: Some of the views contrasting the beneficial and toxic effects of antimicrobials upon wound healing remain controversial. Objective: To assess the clinical relevance of histological findings following antimicrobial applications on chronic leg ulcers. Method: The present study was performed in three parallel groups of 17 patients suffering from at least 2 similar chronic leg ulcers. Clinical planimetric assessments were performed before and after 3 and 6 weeks of treatment using hydrocolloid dressings. In addition, 1 ulcer in each patient received applications of povidone-iodine (PVP-I), silver sulfadiazine or chlorhexidine digluconate. Histological examinations were made at inclusion and after the 6-week therapy. Time to healing was also recorded. Results: At entry in the study, fibroblasts, macrophages, neutrophils and vessels were abundant in the ulcers. In addition, focal necrotizing vasculitis was related to the microbiological load. Compared to the control lesions, both the healing rate and time to healing of the leg ulcers showed a modest improvement at the sites receiving silver sulfadiazine (2–7%) or chlorhexidine digluconate (–1 to 5%). By contrast, PVP-I increased significantly the healing rate (4–18%, p < 0.01), and time to healing was reduced by 2–9 weeks (p < 0.01). The 3 antimicrobials decreased the bacterial density, and the vascular margination and migration of inflammatory cells, thus abating the vasculitic changes. PVP-I applications did not alter the microvessels and did not significantly reduce the density in dendrocytes and fibroblasts. By contrast, both silver sulfadiazine and chorhexidine digluconate appeared to alter the superficial microsvasculature including the dendrocyte population. Conclusion: Although topical antimicrobials may apparently achieve almost similar activity on the bacterial load inside chronic leg ulcers, the toxicity upon host cells was different among these agents. PVP-I appeared to be an efficient compound in these respects exhibiting a positive and relevant clinical effect.

Melanocytic naevi may grow more rapidly during human growth hormone (hGH) therapy. With standardised skin photographs, the growth rate of the naevi was two-fold greater in 14 hypopituitary and 5 Turner's syndrome girls treated with hGH than in untreated patients or controls. HMB-45 immunoreactivity, a marker of stimulated melanocytes, was absent in naevi from 18 of 19 individuals not treated with hGH, including 5 Turner's syndrome patients studied 2-43 months after stopping hGH. In naevi from 39 hGH-treated patients, 22 showed unusual HMB-45 reactivity in dermal naevocytes. During administration of hGH, melanocytic naevi grow faster and there is reversible stimulation of naevocytes.

It is currently agreed that ambient temperature influences the sebum excretion rate. By using the Sebutape technique we have confirmed this concept, which is related to an increased delivery of sebum to the surface of the skin without an increment in the number of active sebaceous follicles.