Immune checkpoint inhibitors can sometimes cause unexpected skin side effects. Special attention should be paid to a severe form of erythema multiforme (EM), toxic epidermal necrolysis and Stevens-Johnson syndrome. We experienced a patient who took 10 weeks from drug discontinuation to the onset of EM major.

Dupilumab is a monoclonal antibody against the alpha subunit of the interleukin (IL)-4 receptor that inhibits IL-4 and IL-13 signaling, which plays a central role in Th2 inflammation in AD.

Here, we report the first Asian case of psoriasis unexpectedly induced by dupilumab therapy for AD. Compared with European and American AD phenotype, Asian AD phenotype is characterized by changes in the psoriasiform phenotype, associating with higher Th17 activation. The blockade of IL-4/IL-13 signaling by dupilumab may induce psoriasis eruption corresponding to shift from a Th2- to Th17- mediated inflammatory response in the skin.

In recent years of immunology, the understanding of innate immunity has deepened, and the concept of innate immunity has been proposed even in the area of acquired immune subjects. The conventional immunosuppressive treatments have mainly controlled the step of acquired immunity. However, the involvement of innate immunity was clarified for hydroxychloroquine (HCQ), which has been confirmed to be very effective for cutaneous lupus erythematosus (CLE). This review introduces the mechanism of development of CLE from the viewpoint of autoantibodies, cytokines, and innate immunity. Furthermore, the mechanism of HCQ is introduced and discussed.

Treatment of malignant melanoma has made great strides in the last decade. On the one hand, immune checkpoint inhibitors and molecular targeted drugs improved the prognosis of patients. On the other hand, it is very important to be aware of the causes of malignant melanoma based on the latest knowledge. In this review, I will briefly review the carcinogenic mechanism of malignant melanoma from the aspects of ultraviolet rays, mechanical stress, trauma and so on.