[Reticular pigmented anomaly of the flexures. Dowling-Degos disease of the intertrigo type in association with acne inversa]. / Retikuläre Pigmentdermatose der Beugen. M. Dowling-Degos vom intertriginösen Typ in Assoziation mit Acne inversa.

Reticulated pigmented anomaly of the flexures (Dowling-Degos disease) is a rare autosomal-dominant genodermatosis with variable penetrance that is characterized by reticulated hyperpigmentation of the flexures. Acne inversa has been previously described in the literature under several synonyms, such as acne triad, acne tetrad and hidradenitis suppurativa. Acne inversa is an inflammation affecting the pilosebaceous units of the flexures. We report a case of Dowling-Degos disease in association with acne inversa. The association of these diseases has been described several times and it appears not to be coincidental. Pathogenetic mechanisms leading to this coincidence are discussed.

Cutaneous polyarteritis nodosa.

Here we present two characteristic cases of cutaneous polyarteritis nodosa (cutaneous PAN). Cutaneous PAN is characterized by a chronic relapsing benign course over many years. In its mild form it presents with live-do and multiple painful nodular skin lesions mainly of the legs. In its more severe form painful skin ulcerations occur that are often accompanied by discrete polyneuropathy. Progression to systemic PAN is the exception. Only the more severe kinds of cutaneous PAN require a low-dose immuno-suppression. Assessment and treatment of cutaneous PAN are discussed.