By Gary M. White, MD
Prurigo pigmentosa is the sudden onset of intensely pruritic, erythematous papules in a reticulate distribution which within weeks leave a reticulated pattern of hyperpigmentation.
Initially, the patient develops symmetric, erythematous, pruritic papules in a reticular pattern on the trunk, neck and antecubital fossa. This phase usually transitions within a week or so to reticulate post-inflammatory hyperpigmentation, which can resemble confluent and reticulated papillomatosis or macular amyloidoisis. In fact, some have theorized that this is an acute and inflammatory form of CRP (think of it if you see "CRP" that itches!). A rare bullous form occurs [JAMA Derm 2014;150;1005].
If ketosis is associated, stopping the dieting, initiating insulin therapy or otherwise correcting the ketosis clears the skin. Otherwise, oral minocycline (e.g., 100 mg po BID) is usually very effective. Indeed, any of the antibiotics used for CRP may be tried here. Alternatively, dapsone 25-100 mg/d, sulfamethoxazole, and sunlight have been used.
Here, the residual pigmentation is shown.
Dermatology Online Journal 17 (12): 2
J Am Acad Dermatology 69, Issue 4, Pages e193–e195, October 2013
A sugar-free diet seemed to precipitate this rash. JAAD September 2014 Volume 71, Issue 3, Pages e61–e62
Homepage | FAQs | Use of Images | Contact Dr. White