Dialysis-associated pseudoporphyria successfully treated with vitamin D. Report of two cases.

Pseudoporphyria refers to a rare bullous dermatosis characterized by the clinical and histological features of porfiria cutanea tarda without abnormalities in porphyrin metabolism. The pathogenesis is heterogeneous and several exogenous factors may promote the bullous lesion formation, including medications, end stage renal disease, dialysis and tanning beds. Regarding treatment of this condition, in literature different therapy have been reported, such as glutathione and his precursor N-acetylcysteine, which presents anti-oxidant properties; however even more toxic drugs, such as chloroquine, are used. Moreover, in patients with drug-induced PP discontinuation of the offending agent, if possible, is a crucial aspect of the clinical management. We report two cases of dialysis patients presenting blisters on extremities, which healed with the avoidance of UV exposure and oral Vitamin D supplementation. Interestingly Vitamin D despite the lack of antioxidant properties led to a completely resolution of PP in both our patients within 30 days. A possible explanation of this finding is that Vitamin D, playing a key role in the regulation of serum Ca2+, can modulated cadherin-cadherin interactions and led to healing of pseudoporphyria bullous lesions. Finally we highlight the prominent role of UV-exposure in PP elicitation thus a good photoprotection is essential for all patients with pseudoporphyria.

Multiple skin ulcers due to Serratia marcescens in a immunocompetent patient.

Serratia marcescens is a species of gram negative bacillus, classified as a member of the Enterobacteriaceae, mainly involved in opportunistic infections, particulary in the hospital environment. Cutaneous infections have rarely reported in literature and are predominantly observed in elderly or in immunocompromised patients. The clinical manifestations of skin infections include granulomatous lesions, necrotizing fasciitis, nodules, cellulitis, ulcers, dermal abscesses. Infections caused by S. marcescens may be difficult to treat because of resistance to a variety of antibiotics, including ampicillin and first and second generation cephalosporins. Aminoglycosides have good activity against S. marcescens, but resistant strains have also been described. We report a very intriguing case of S. marcescens infection, in an immunocompetent 18-year-old man, causing multiple rounded ulcers of varying sizes, along with few pustular lesions that both clinically and histopathologically mimic a pyoderma gangrenosum (PG). This is a non infectious neutrophilic skin disorder, characterized by painful and rapidly progressing skin ulceration. According to our experience, we would strongly recommend to perform cultures of multiple skin ulcers resembling PG, even in young healthy patients, to ensure correct diagnosis and treatment, since resistant to conventional antibiotics bacteria such as S. marcescens may be the cause of these lesions, like in the case here reported.