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There is growing evidence that not only the novel coronavirus disease (COVID‐19) but also the COVID‐19 vaccines can cause a variety of skin reactions. In this review article, we provide a brief overview on cutaneous findings that have been observed since the emerging mass COVID‐19 vaccination campaigns all over the world. Unspecific injection‐site reactions very early occurring after the vaccination are most frequent. Type I hypersensitivity reactions (e.g. urticaria, angio‐oedema and anaphylaxis) likely due to allergy to ingredients may rarely occur but can be severe. Type IV hypersensitivity reactions may be observed, including delayed large local skin lesions (“COVID arm”), inflammatory reactions in dermal filler or previous radiation sites or even old BCG scars, and more commonly morbilliform and erythema multiforme‐like rashes. Autoimmune‐mediated skin findings after COVID‐19 vaccination include leucocytoclastic vasculitis, lupus erythematosus and immune thrombocytopenia. Functional angiopathies (chilblain‐like lesions, erythromelalgia) may also be observed. Pityriasis rosea‐like rashes and reactivation of herpes zoster have also been reported after COVID‐19 vaccination. In conclusion, there are numerous cutaneous reaction patterns that may occur following COVID‐19 vaccination, whereby many of these skin findings are of immunological/autoimmunological nature. Importantly, molecular mimicry exists between SARS‐CoV‐2 (e.g. the spike‐protein sequences used to design the vaccines) and human components and may thus explain some COVID‐19 pathologies as well as adverse skin reactions to COVID‐19 vaccinations.

Optical coherence tomography (OCT), a fairly new non-invasive optical real-time imaging modality, is an emergent in vivo technique, based on the interference (Michelson interferometry) of infrared radiation and living tissues, that allows high-resolution, 2- or 3-dimensional, cross-sectional visualisation of microstructural morphology of tissues. OCT provides depth-resolved images of tissues with resolution up to a few micrometers and depth up to several millimetres depending on tissue type. The investigations using OCT to assess skin structure in clinical settings started in the past decade and consequently proved that this imaging method is useful in visualizing subsurface structures of normal skin, including the epidermis, dermoepidermal junction, dermis, hair follicles, blood vessels and sweat ducts. An increasing number of papers brought evidence of the utility and the precision of OCT technology, in its different technical variants, in diagnosing and monitoring skin disorders, including malignancies and inflammatory conditions, respectively. The present comprehensive review describes and illustrates technical aspects and clinical applications of OCT methods in dermatology.

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Anal carcinoma and AIN are frequent in HIV-positive men, even in patients participating in anal cancer prevention programmes. High-grade dysplasia in these patients can progress to invasive cancer within a short period of time. Anal margin carcinoma and anal canal carcinoma differ substantially in their lesional HPV spectrum, prognosis and treatment response.