In Milan, Italy, after the end of the lockdown period (March and April 2020), we observed several patients with seborrheic dermatitis (SD) who showed a more or less important worsening of their disease. All patients used anti‐coronavirus‐19 (COVID‐19) face mask for many hours per day. According to the clinical point of view, the worsening was characterized by increased erythema and desquamation as well as itching worsened. In the last few weeks, some articles have been published on cases of dermatitis of the face associated with the use of anti‐COVID‐19 masks. Some authors hypothesized that this condition is due to high temperature of the face covered by the mask, that induces an increased sebum excretion rate. In our patients with SD, it is possible that high temperature of the face induces abnormalities of microbiota (proliferation of
Malassezia
spp.?) and permeability of skin barrier, and increases sweating with irritant action and worsening of itching.