ABSTRACT
Psoriatic onycho-pachydermo-periostitis (POPP) is a rare subset of psoriatic arthritis. It is usually localized to the hands and it is characterized by onychodistrophy, soft tissue thickening above the distal phalanx and periosteal reaction. The resolution is very slow due to the involvement of nails and bone. Low dose methotrexate and anti-tumor necrosis factor-α (anti-TNF-α) agents are the suggested therapies. We report a case of a 53-year-old man affected by palmo-plantar slight psoriatic dermatitis, who presented a rapid onset of POPP. Rx imaging showed enthesitis and a moderate phalanx erosion with articular spaces narrowing and swollen periosteal reaction. A magnetic resonance imaging test of the hands showed an initial stage of synovitis and extensive periostitis of the distal phalangeal tufts. The patient has been treated with oral methotrexate for a month with a rapid clinical improvement and pain reduction. As POPP at first manifests as a painful onycodistrophy, it can easily be confused with bacterial perionyxis. The delay in making the correct diagnosis, and therefore, the delay in giving a proper treatment would mean the progressive articular erosion and the permanent invalidation of the patient's ability to use his hands.
ABSTRACT
Erythema elevatum diutinum (EED) is a localized, low-grade form of leukocytoclastic vasculitis mainly affecting adults, with only a few pediatric cases reported in the literature. The pathogenesis of this dermatosis is unknown, although an Arthus-type reaction to bacterial and viral antigens seems involved. We describe a case of EED in a 9 year-old child suffering from recurrent pharyngotonsillitis induced by Streptococcus pyogenes. Clinical presentation of the dermatosis was atypical, with vesicles and bullae intermingled with red-purple papules and plaques distributed mainly over the extensor aspects of the extremities. Histopathological examination of a vesiculo-bullous lesion revealed a subepidermal bulla containing neutrophils and nuclear dust suggesting dermatitis herpetiformis. Fibrin in vessel walls was observed throughout the dermis. Direct immunofluorescence was negative. A prompt and complete response to sulphone therapy was obtained in conjunction with tonsillectomy. Clinicians should be aware of atypical presentations of EED in children with vesicles and bullae mimicking During's disease.
