LAUSR

were observed (Fig. 2a). Neutrophils were also found in the epidermis. Inflammatory cells mostly consisted of lymphocytes and eosinophils (Fig. 2b). We diagnosed the cutaneous eruption as an eczematous reactions mimicking psoriasiform dermatitis. She responded quickly to a topical steroid (clobetasol propionate 0.05%) and oral antihistamine (olopatadine), with no recurrence (Fig. 1b,d,f). Clinically, this case was similar to previous reported cases of psoriasiform dermatitis. However, acanthosis rather than epidermal hyperplasia and eosinophil infiltration were prominent, suggesting an eczematous reactions rather than psoriasiform dermatitis. Radiation recall dermatitis reflects the ‘recalling’ of radiotherapy-induced skin reactions in the previously irradiated skin regions in response to the introduction of certain response-inducing agents. However, in our case, the cutaneous eruption spared the previously irradiated skin. Although the mechanisms have not elucidated, therapy-refractory eczema and/or psoriasis can be successfully treated with radiotherapy. Thus, her previous irradiation may have suppressed the eczematous reaction over the left upper abdomen. In summary, physicians should be aware of the eczematous reactions mimicking psoriasiform dermatitis, even after cessation of checkpoint inhibition therapy.