Prurigo pigmentosa: not that uncommon? First case in Central and Eastern Europe. Dermoscopy

Prurigo pigmentosa (PP) is a rare skin condition described first by Nagashima in 1971 [1]. Since then 259 cases have been described outside Japan, of which only 21 in Europe (Spain, Germany, Italy, Austria, Sweden). Usually PP is diagnosed in young people, mostly in their second and third decade of life [2]; the majority of patients are female; it affects women 4 to 7 times more frequently than men [3]. The cause of PP is unknown; one of the theories suggests a connection between the disease and ketosis during a restrictive diet and diabetes [3, 4].
The skin lesions are reticular and located symmetrically on the torso (usually the chest, the upper back, the lumbosacral region) and often also on the neck, the abdomen, the arms and the forehead. The evolution of the lesions, both morphological and histopathological, is characteristic for PP. In the initial stage lasting 2–3 days, intensively itching erythematous and oedematous papules appear. Within a week the lesions undergo regression and leave fuscous and brown patchy hyperpigmentation which remains on the skin up to several months. Significantly, the lesions in various stages of development can occur concomitantly [2]. In the histopathological image, the papillary dermal oedema with hyperkeratosis (orthokeratotic), necrotic keratinocytes (few), neutrophilic infiltrates (sparse and perivascular) and spongiosis (mild) are initially visible.
Fully developed, intensively itching, swollen papules are histologically visible as extravasation of erythrocytes, hyperkeratosis (orthokeratotic), lymphocytic infiltrates (patchy and lichenoid), necrotic keratinocytes (numerous) and spongiosis (moderate). The final stage of hyperpigmentation is dominated by hyperkeratosis (parakeratotic), neutrophilic infiltrates (sparse and perivascular) and melanophages in papillary dermis [2].
The patients most frequently seek consultation when the lesions are in an advanced stage of development; therefore, during the differential diagnosis, reticulate pigmentary disorders which become apparent in adults in good general health should be taken into account, such as confluent and reticulated papillomatosis (Gougerot-Carteaud syndrome), erythema ab igne, atopic dirty neck, Dowling-Degos disease, Galli-Galli disease, postinflammatory and drug-induced dermatoses [5].
Oral antibiotics, such as minocycline [6], doxycycline [7] and macrolides [8] as well as dapsone [2] are successfully used during treatment; however,...


View full text...