Cutaneous histiocytic lymphangitis: an unusual manifestation of rheumatoid arthritis.

Two cases are presented of unusual cutaneous lesions associated with rheumatoid arthritis in underlying joints. The lesions were evanescent, erythematous and violaceous partly macular and partly indurated plaques, with a livedo-like pattern of erythema at the edge in one case. Histological changes were identical in the two cases. The major features were dilated, dermal lymphatics containing aggregates of inflammatory cells, mainly histiocytes, with adjacent perivascular lymphoid aggregates. An appropriate name for this reaction would appear to be cutaneous histiocytic lymphangitis.

Do people who apply sunscreens, re-apply them?

Little is known about Australians' practices regarding sunscreen re-application, yet it is routinely advised and has recently been shown to increase the protective efficacy of sunscreens. A baseline survey of sunscreen application and re-application behaviour was therefore conducted in a Queensland community using a standard self-administered questionnaire. Other sun protection methods were also assessed. Of a total of 669 adult respondents, 76% reported using sunscreen and of those, 61% reported re-applying sunscreen. Significantly more women (66%) than men (55%) reported re-applying sunscreen and re-application was inversely related to age (79% of those aged less than 45, 57% of those 45-59 years old and 46% of those over 60 years). Increased rates of re-application were reported during times of increased sun exposure, as well as by those with greater knowledge of the benefits of sunscreen re-application. A recent personal history of non-melanoma skin cancer did not lead to improved rates of sunscreen application, sunscreen re-application, or most forms of physical sun protection.

Photobiological aspects of sunscreen re-application.

A single application of a high sun protection factor (SPF) sunscreen has been shown to prevent sunburn, but the existence of a further protective effect following re-application of sunscreen has received little attention. The aim of this study was to quantify the ultraviolet radiation (UVR) protection against sunburn afforded by a re-application of sunscreen relative to a single application. The study methods were based on the Australian Standard SPF testing regimen, using human volunteers, standardized applications of sunscreen and an artificial solar simulating UVR source. Sunscreen was initially applied, followed by a suberythemal UVR dose; sunscreen was then re-applied, followed immediately by a second period of controlled UV exposure sufficient to induce mild erythema. Compared to the first application, the second sunscreen application afforded 3.1 times more protection against minimal UVR-induced erythema. The combined effect of two sunscreen applications gave on average 2.5 times better protection from UVR than a single sunscreen application. Health authorities worldwide have recommended sunscreen re-application for the prevention of sunburn for some time. This is the first quantitative study to substantiate such recommendations.