Correspondence: A case of prurigo pigmentosa successfully treated with minocycline

Post bariatric surgery prurigo pigmentosa in an adolescent

Prurigo pigmentosa is an inflammatory skin condition that is characterized by the presence of pruritic reticulated hyperpigmented papules or vesicles of the upper trunk. Previously, this condition was rarely encountered until the rise in popularity of weight reduction methods. Even with the increased prevalence, most affected patients are still adults. We present the case of an adolescent who was successfully treated with doxycycline and encouraged to resume eating.

Prurigo pigmentosa: a distinctive inflammatory disease of the skin

More than 200 patients with prurigo pigmentosa, a disease described first by Nagashima in 1971, have been reported on in Japan, but only 28 non-Japanese patients have come to notice as of today. In order to establish reliable, repeatable criteria for diagnosis of the disease, we studied 25 patients with prurigo pigmentosa and reviewed the literature pertaining to it as recorded in another 182 patients.Clinically, prurigo pigmentosa presents itself as pruritic urticarial papules, papulovesicles, and vesicles arranged in reticular pattern and distributed symmetrically on the back, neck, and chest. Lesions involute in a matter of days, leaving behind netlike pigmentation. Exacerbations and recurrences are the rule. Histopathologically, prurigo pigmentosa begins with a superficial perivascular infiltrate of neutrophils. Shortly thereafter, neutrophils are scattered in dermal papillae and then sweep rapidly through an epidermis in which spongiosis, ballooning, and necrotic keratocytes are accompaniments. En route, abscesses may form in the surface epithelium. Very soon, eosinophils and lymphocytes come to predominate over neutrophils in a dermal infiltrate that assumes a patchy lichenoid pattern. Intraepidermal vesiculation follows on spongiosis and ballooning and, sometimes, subepidermal vesiculation on vacuolar alteration at the dermo-epidermal junction. As the epidermis becomes hyperplastic, parakeratotic, and slightly hyperpigmented, melanophages begin to appear in the dermis. Studies by immunofluorescence are negative invariably. Dapsone or minocyclin are effective treatments; both of those agents inhibit migration and/or function of neutrophils. The cause and pathogenesis have yet to be determined. Prurigo pigmentosa is unique among inflammatory diseases of the skin and the singularity of it is manifest both clinically and histopathologically.

Prurigo pigmentosa

BACKGROUND

Prurigo pigmentosa is a rare inflammatory dermatosis of unknown etiology characterized by recurrent, pruritic erythematous papules and gross reticulate hyperpigmentation. It is seen most commonly among young adult Japanese females. Only 20 cases have been described outside Japan.

METHODS

We report two female, Turkish patients aged 20 and 26 years who had a pruritic rash with the characteristic clinical appearance and supportive histopathology of prurigo pigmentosa.

RESULTS

They were successfully treated with minocycline and doxycycline.

CONCLUSIONS

Prurigo pigmentosa is a relatively new clinical entity, and we believe that a more widespread knowledge of this disease will lessen its misdiagnosis. We find it noteworthy to point out that there may be a predisposition to prurigo pigmentosa amongst the Turkish and Sicilian populations.