The COVID-19 pandemic gave rise to an increased occurrence of skin-related issues stemming from the use of face masks and intensified hand hygiene. This study delved into the skin complications experienced by 695 patients and their family members who sought care in the dermatology departments of three hospitals. Notably, women exhibited a higher prevalence of acne, itching, and facial redness attributed to mask-wearing, with acne predominantly affecting the younger patient demographic. A noteworthy association was also observed between the frequency of hand washing and disinfection and the incidence of hand skin lesions. Those who engaged in hand washing and disinfection more than ten times daily were found to be at an elevated risk of developing skin lesions on their hands. The findings of this study, together with relevant international literature and recommended preventive measures, are discussed.

In severe cases, cholinergic urticaria can lead to angioedema and anaphylactic shock; a definitive diagnosis and confirmation of its severity are required. We experienced two cases in their 20s of severe cholinergic urticaria with anaphylactic symptoms and confirmed the diagnosis and severity of the disease by the exercize challenge test. Both cases were complicated by atopic dermatitis, and the symptoms were severe at the eczema site. In addition, complications of bronchial asthma and food allergies are also recognized. Definitive diagnosis and control of each disease are important in the diagnosis, treatment, and management of cholinergic urticaria.

COVID-19 mRNA vaccination causes various cutaneous reactions. However, development of de novo pustular psoriasis following COVID-19 vaccination is rare. We herein report two cases of pustular psoriasis that developed after COVID-19 mRNA vaccination. The first case, a 26-year-old female, complained of fever and generalized erythematous rash with pustules that had started the day after Moderna COVID-19 vaccination. The second case, an 80-year-old male, developed erythematous eruptions the day after Pfizer COVID-19 vaccination. One month later, he experienced fever and generalized pustules on erythematous lesions. We diagnosed both cases as pustular psoriasis. Treatments including prednisolone and cyclosporine for the first case and prednisolone, etretinate and secukinumab for the second case improved their symptoms. Although development of pustular psoriasis after COVID-19 vaccination is rare, careful observation is needed when a widespread rash appears.