Infectious skin diseases: main defense mechanisms and consequences of infectious diseases

The skin provides complex immune protection through innate immunity (physical barrier of the stratum corneum, antimicrobial lipids, resident microflora, secretory IgA) and adaptive immunity (skin-associated lymphoid tissue (SALT), including Langerhans cells, lymphocytes). Disruption of these mechanisms leads to serious infectious consequences: bacteria (S. aureus, S. pyogenes) cause impetigo, erysipelas, psoriasis; viruses (SARS-CoV-2) provoke hair loss and rashes; parasites (leishmania, sand fleas) lead to scars, deformations, tungiasis; fungal infections (dermatophytosis, mycetoma, coccidioidomycosis, zygomycosis) cause persistent scars, alopecia, necrosis. Understanding these relationships is critical for developing effective strategies for the treatment and prevention of skin infections and their complications.