Discussion
To our knowledge, we report the first case of EED with skin lesions involving the scalp, and the first case of EED improved with the treatment of IVIg. According to the current reports, EED skin lesions mostly occur in the limbs, especially in the joints(4). Recently, it has been reported that EED lesions can occur in some atypical sites such as the trunk and palm, and these EED cases have been reported to be related to non-Hodgkin lymphomas and IgA gammopathy(5, 6). These cases have a good response to the therapy. However, our case is more peculiar. This case shows a history of pulmonary tuberculosis and abnormal levels of IgG and IgA. In addition, lesions of this patient were distributed not only on the trunk and plantar surface but also on the scalp. Furthermore, this case showed an ineffective response to dapsone and corticosteroids. Therefore, we speculate that EED with multiple underlying diseases as well as the lesions involving the atypical sites has a poor response to traditional treatments such as dapsone and corticosteroids.
In addition, this patient showed a sensitive response to IVIg with no obvious side effects. IVIg is thought to interrupt the steps of the complement activation cascade and down-regulate B cell proliferation(7). It has been proved to have a good curative effect in patients with pemphigus, dermatomyositis, and scleroderma. In the literature we retrieved so far, this is the first case of IVIg in the treatment of EED. A large number of literature have reported that dapsone has been successfully used in the treatment of EED, but still showed poor efficacy in about 20% of patients(8). Treatment for refractory EED should also be considered. For those patients with a poor response to dapsone and corticosteroids or intolerant to dapsone, this case provides another option for the treatment of EED. However, because this is the first case of EED treated with IVIg, its efficacy should be confirmed by more patients with longer follow-up.