Rosacea is a chronic, relapsing inflammatory facial dermatosis characterized by flushing, persistent erythema, telangiectasias, papules, pustules, and phymatous changes. Driven by dysregulated innate immunity, neurovascular hyperreactivity, and skin microbiome alterations,…

Bed bugs (Cimex lectularius) are small, wingless, reddish-brown parasitic insects belonging to the family Cimicidae. As nocturnal hematophagous ectoparasites, they feed preferentially on human skin during sleep. Global resurgence has…

Lyme disease (Lyme borreliosis) is a systemic, tick-borne infection caused primarily by the spirochete Borrelia burgdorferi (and less commonly Borrelia mayonii in North America). As the most common vector-borne illness…

Angular cheilitis—also referred to as angular stomatitis, perlèche, or cheilosis—is an inflammatory perioral condition localized to the commissures of the mouth. Driven primarily by opportunistic fungal (Candida) or bacterial infections,…

Cellulitis and cutaneous abscesses are prevalent bacterial skin and soft tissue infections (SSTIs) primarily driven by gram-positive cocci. Distinguishing non-purulent tissue involvement (cellulitis) from focal purulent fluid collections (abscess) is…

Verruca vulgaris (common warts) are benign epidermal hyperplasias caused by infection with non-oncogenic strains of Human Papillomavirus (HPV). Transmitted via direct skin contact or autoinoculation, clinical management relies on distinguishing…

Skin cancer encompasses precancerous dysplasias, non-melanoma skin cancers (NMSC), and cutaneous malignant melanoma. Early clinical identification through diagnostic mnemonics, prompt histological biopsy confirmation, and appropriate surgical or topical interventions are…

Seborrheic dermatitis is a common, chronic-relapsing inflammatory skin disease affecting sebum-rich areas of the head, face, and trunk. Driven primarily by an abnormal inflammatory immune response to commensal Malassezia yeasts,…

Psoriasis vulgaris is a chronic, immune-mediated inflammatory skin disorder driven by T-cell-mediated hyperproliferation of keratinocytes and incomplete cell maturation. Characterized by well-demarcated erythematous plaques covered with silvery scales, effective long-term…