Proteus syndrome (PS) is a complex hamartomatous disorder defined by local overgrowth (macrodactyly or hemihypertrophy), subcutaneous tumours and various bone, cutaneous and/or vascular anomalies (VA). VA are manifold in PS, but their prevalence is unknown so far. In order to further characterize PS, we studied the prevalence of VA in 22 PS patients presenting to our outpatient clinic and reviewed 100 PS patients previously reported between 1983 and 2001. The diagnosis of vascular abnormalities was made on clinical grounds and supported with imaging studies and/or histology in 12 and seven patients out of 22, respectively. Thirty-five VA were identified in 22/22 (100%) of our patients, and more than one type of VA were present in 10 of them. Vascular tumours, portwine stains (PWS), and venous anomalies (varicosities, prominent veins) were equally common. A total of 118 VA were previously reported in 70/100 (70%) PS patients; vascular hamartomas were more prevalent (56/118 = 47.5%), whilst PWS (21.2%) and venous anomalies (22.9%) were slightly less common than in our series, but there is the possibility of under-reporting. Unlike Klippel-Trenaunay syndrome, where VA are mostly confined to the hypertrophic limb, major arteriovenous anomalies are rare, and - similar to the other hamartomas and naevi observed in PS (pigmentary naevi, epidermal naevi, subcutaneous tumours, exostoses) - VA appear to be distributed at random sites on the body. We conclude that VA are among the most common findings in PS. Their varying type and distribution lend further support to the concept of somatic mosaicism.

Arcanobacterium haemolyticum has been described as an unusual pathogen causing pharyngotonsillitis and systemic disease in patients with predisposing conditions. A case of soft tissue abscess with no apparent portal of entry is reported in a healthy 31-year-old man who presented with a breast tumor. A second case of abscess formation in a 50-year-old patient with complicated wound healing is presented. In addition, a case of Arcanobacterium haemolyticum cellulitis in a 25-year-old female is reported. Due to its innocuous, coryneform appearance, this pathogen is probably underreported; therefore, the diagnostic evaluation of this organism is emphasized.

A 12 year old boy developed scars at light-exposed areas following long-term therapy with naproxen for rheumatoid arthritis. Erythrocyte and urine porphyrin levels were not increased, and there was no evidence of increased photosensitivity. Pseudoporphyria is reported in 10-20% of those treated with naproxen for > 4 weeks. As compared to other nonsteroidal anti-inflammatory agents, the specific risk for naproxen is increased about 6fold. While the underlying abnormality has not been elucidated, formation of phototoxic metabolites in a subgroup of genetically predisposed individuals has been suggested as the most likely mechanism. Both dermatologists and rheumatologists should be aware of the risk of naproxen-induced pseudoporphyria and discontinue therapy early in order to avoid scar formation in light-exposed areas.