Update: Treatment of necrobiosis lipoidica

Necrobiosis lipoidica (NL) is a rare granulomatous disease of hitherto unclear etiology frequently seen in patients with diabetes. Characterized by its potential for ulcerations, it often presents a serious burden for those affected. There are currently neither German nor European guidelines for the treatment of NL. At the same time, standard treatment with topical or intralesional corticosteroids does not always show satisfactory results. We therefore set out to evaluate whether the various treatment regimens published since 2000 have actually expanded the therapeutic armamentarium in a relevant manner. Included were all publications that described more than one patient being treated with any given therapeutic modality. Overall, we analyzed data for 16 different treatment regimens reported in 49 publications. The largest amount of data exists for topical PUVA therapy, photodynamic therapy (PDT), and systemic treatment with fumaric acid esters. Remarkably, our analysis showed that with an increase in the number of documented patients treated with a given therapeutic modality, the proportion of those achieving a complete or partial response actually decreased. This was interpreted as publication bias. Thus, no clear recommendation can be given for second-line therapy in case topical or intralesional corticosteroids fail.