Doxycycline - An emerging therapy for prurigo pigmentosa

摘要

Editor Prurigo pigmentosa is a rare, idiopathic inflammatory dermatosis that was first reported in Japan in 1971. It is characterized by an initial eruption of pruritic macules and papules, which subsequently evolves into a reticulate pattern of hyperpigmentation upon resolution.Minocycline and dapsone have most frequently been reported to successfully treat prurigo pigmentosa. Both drugs work by inhibiting the migration and function of neutrophils. A prominent adverse drug reaction from minocycline use is the development of hyperpigmentation, which has an estimated incidence of 3-5%. Although cessation of minocycline therapy often results in resolution of the hyperpigmentation, the signs may persist and can be severe. On the other hand, dapsone poses the risks of haemolytic anaemia, agranulocyctosis and hepatocellular damage. Its use requires screening for glucose-6-phosphate dehydrogenase deficiency and monitoring of full blood counts and liver function. Tetracycline has also been tried, but studies have shown conflicting results.6 Other drugs that have been used with varying success include potassium iodide, sulphamefhoxazole, macrolides such as clarithromycin and roxithromycin, as well as isotretinoin.