The pandemic condition Coronavirus‐disease (COVID‐19), caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) can take asymptomatic, mild, moderate, and severe courses. COVID‐19 affects primarily the respiratory airways leading to dry cough, fever, myalgia, headache, fatigue, and diarrhea and can end up in interstitial pneumonia and severe respiratory failure. Reports about the manifestation of various skin lesions and lesions of the vascular system in some subgroups of SARS‐CoV‐2 positive patients as such features outside the respiratory sphere, are rapidly emerging. Vesicular, urticarial and maculopapular eruptions as well as livedo, necrosis and other vasculitis forms have been reported most frequently in association with SARS‐CoV‐2 infection. In order to update information gained, we provide a systematic overview of the skin lesions described in COVID‐19 patients, discuss potential causative factors and describe differential diagnostic evaluations. Moreover, we summarize current knowledge about immunologic, clinical and histologic features of virus‐ as well as drug‐induced lesions of the skin and changes to the vascular system in order to transfer this knowledge to potential mechanisms induced by SARS‐CoV‐2.

A semen allergy is a type I reaction. Reliable figures about incidence/prevalence are not available. Symptoms can be characterized as local and systemic. After exposure to ejaculate, the patient may experience itching and swelling at points of contact, while systemically it may also lead to generalized urticaria with angioedema or higher grade anaphylaxis. As triggering allergens, substances in seminal plasma (SP) have been identified, which can be SP typical or SP atypical. Reactions against spermatozoa have not yet been clearly proven. With regard to SP-typical allergens, prostate-specific antigen (PSA) has been identified, while for SP-atypical allergens, medications or food allergens have been reported, which apparently accumulate in the SP and can then trigger symptoms in women with existing sensitization. The main criteria for the diagnosis of sperm allergy is freedom from symptoms when condoms are used during intercourse. In addition, skin prick tests and determination of allergen-specific IgE are used. In patients with a desire for children, washed, SP-free spermatozoa can be used for insemination. In addition, desensitization may be considered.