Cutaneous manifestations of COVID-19

Cutaneous manifestations of COVID-19 are characteristic signs or symptoms of the Coronavirus disease 2019 that occur in the skin. The American Academy of Dermatology reports that skin lesions such as morbilliform (measles-like rashes, 22%), pernio (capillary damage, 18%), urticaria (hives, 16%), macular erythema (rose-colored rash, 13%), vesicular purpura (purplish discolouration, 11%), papulosquamous purpura (discolouration with scale. 9.9%) and retiform purpura (blood vessel obstruction and downstream ischaemia, 6.4%) are seen in people with COVID-19.^[1]^[2]^[3] Pernio-like lesions were more common in mild disease while retiform purpura was seen only in critically ill patients.^[1] The major dermatologic patterns identified in individuals with COVID-19 are urticarial rash, confluent erythematous/morbilliform rash, papulovesicular exanthem, chilbain-like acral pattern, livedo reticularis and purpuric "vasculitic" pattern.^[4] Chilblains and Multisystem inflammatory syndrome in children are also cutaneous manifestations of COVID-19.^[5]

Hyperactive immune responses in COVID-19 patients can contribute to the induction "cytokine storm" (in particular, IL-6); these cytokines could enter the skin and trigger dermal dendritic cells, lymphocytes, macrophages, mast cells, and neutrophils, and can assist in the development of lesions such as maculopapular rash. This representation of cutaneous lesion has been described earlier in diseases having an overactive immune response and excessive cytokine release (example, systemic lupus erythematosus, adult Still's disease, and antiphospholipid syndrome).^[6]

Urticarial rash

Urticarial rash (hives) is seen in several bacterial and viral infections, so COVID-19 is no exception. These rashes are more commonly found in the trunk and limbs, relatively sparing the acral sites. Systemic corticosteroids are a therapeutic option for urticarial rash induced by COVID-19.^[4]

Confluent erythematous rash

The erythematous rashes (redness caused by increased blood flow through skin capillaries) seen in COVID-19 are mostly present on the trunk and limbs, and associated with itching.^[4] Exanthems induced by viruses other than COVID-19 and drug reactions should be considered as differential diagnosis in the case of erythematous rashes.^[4]

Livedo reticularis

Livedo reticularis refers to slowing of blood flow, leading to desaturation of blood and bluish discolouration of the skin. This type of skin rashes may be seen in cold-induced vasoconstriction as seen in polycythemia or other causes leading up to focal impairment of blood flow.^[4]

Histopathological hallmarks

From the histological (microscopic anatomy) perspective, several features of the maculopapular lesion have been recognized. Maculopapular lesions exhibit superficial perivascular dermatitis with lymphocytic infiltrate and dilated vessels in the papillary and mid dermis with neutrophils, eosinophils, and nuclear debris. Epidermis revealed dispersed foci of hydropic changes, accompanied by minimum acanthosis, subcorneal pustules, slight spongiosis, Basal cell vacuolation, and foci of parakeratosis.^[6] A lichenoid pattern with eosinophils' presence on biopsy of skin lesions has been observed in some patients.^[7]

References

^ ^a ^b Freeman EE, McMahon DE, Lipoff JB, Rosenbach M, Kovarik C, Desai SR, et al. (October 2020). "The spectrum of COVID-19-associated dermatologic manifestations: An international registry of 716 patients from 31 countries". Journal of the American Academy of Dermatology. 83 (4): 1118–1129. doi:10.1016/j.jaad.2020.06.1016. PMC 7331510. PMID 32622888.
^ "COVID-19 dermatology registry". American Academy of Dermatology. Retrieved 1 March 2021.
^ Freeman EE, McMahon DE, Hruza GJ, Irvine AD, Spuls PI, Smith CH, et al. (September 2020). "International collaboration and rapid harmonization across dermatologic COVID-19 registries". Journal of the American Academy of Dermatology. 83 (3): e261–e266. doi:10.1016/j.jaad.2020.06.050. PMC 7833847. PMID 32562840.
^ ^a ^b ^c ^d ^e Genovese G, Moltrasio C, Berti E, Marzano AV (2021). "Skin Manifestations Associated with COVID-19: Current Knowledge and Future Perspectives". review. Dermatology. 237 (1): 1–12. doi:10.1159/000512932. PMC 7801998. PMID 33232965.
^ Feldman SR, Freeman EE (June 2021). Callen J, Duffin KC, Ofori AO, Corona R (eds.). "COVID-19: Cutaneous manifestations and issues related to dermatologic care". UpToDate. Wolters Kluwer. Retrieved 1 March 2021.
^ ^a ^b Shams S, Rathore SS, Anvekar P, Sondhi M, Kancherla N, Tousif S, et al. (March 2021). "Maculopapular skin eruptions associated with Covid-19: A systematic review". review. Dermatologic Therapy. 34 (2): e14788. doi:10.1111/dth.14788. PMC 7995033. PMID 33481314.
^ Kaya G, Kaya A, Saurat JH (June 2020). "Clinical and Histopathological Features and Potential Pathological Mechanisms of Skin Lesions in COVID-19: Review of the Literature". review. Dermatopathology. 7 (1). Basel, Switzerland: 3–16. doi:10.3390/dermatopathology7010002. PMC 7583593. PMID 32608380.