Treatment of nodular prurigo with benoxaprofen SIR, A 60-year-old female patient whom we were treating for nodular prurigo suddenly improved when her family practitioner gave her benoxaprofen (Opren*, Dista) for osteoarthritis. We therefore treated a 55-year-old man who had nodular prurigo affecting both legs for 7 years with benoxaprofen 600 mg daily as sole therapy for 2 months. Treatment was then discontinued and the lesions are now flat and healing with atrophy and scarring. Figure i a shows the typical histology ofa pre-treatment

The Willan Mural Stone at Funchal

Striae are always initiated by stretch whether the stretch is excessive or minimal: spontaneous striae do not occur. Cross-linkage of collagen appears to be more important than amount of collagen in permitting striae in response to stretch. An increase in cross linkage as in age increases the resistance to stretch deformation, but this rigidity leads ultimately to tearing of the skin and not striae. At the other extreme, the absence of crosslinkage leads to "elasticity" and excessive stretching with eventual rupture of the skin if the stretch goes beyond the elastic limit, but again, no striae. Striae appear to occur therefore only in skin in which the rigid cross-linked collagen and "elastic" unlinked collagen thus permitting a limited degree of stretch and a limited intradermal rupture, i.e. striae. (Although rigidity and elasticity are presented here in terms of collagen cross-linkage it seems probable that changes in interfibrillary materials such as glycosaminoglycans will prove important in this respect). This balance of stretch and limited tear is a continuous process and is an adaptation to the needs of growth in adolescence and change in body mass in early adult life and there are many many subclinical "striae" for each gross tear which is recognised clinically. An important factor likewise appears to be rate of stretch since if it is very slow, striae are less likely; there is "give" and new collagen formation. Although this working hypothesis is consonant with the facts only further work will show whether this smooth consonance is that of the fable or the weathered rock of fact.

The Willan Mural Stone at Funchal

References

The cause of striae distensae