Cellulitis

Cellulitis is a common skin infection that affects the deeper layers of the skin and the underlying tissues. It usually occurs when bacteria enter through a break in the skin, causing redness, swelling, warmth, and pain in the affected area. The infection primarily involves the skin and soft tissues, often on the legs or arms. If untreated, it can spread rapidly and lead to serious complications such as abscess formation or bloodstream infection. People with weakened immune systems or chronic conditions like diabetes are at higher risk. The main health impact is localized inflammation that can impair normal skin function and cause systemic symptoms like fever.

Cellulitis is an acute, spreading infection of the dermis and subcutaneous tissues characterized by erythema, edema, warmth, and tenderness. It is most commonly caused by bacterial invasion, typically by Gram-positive cocci such as Staphylococcus aureus and Streptococcus pyogenes, entering through skin breaches. The infection leads to an inflammatory response with infiltration of neutrophils and release of cytokines. Clinically, it presents with localized pain, swelling, and systemic signs such as fever and leukocytosis. The condition is significant due to its potential for rapid progression, risk of complications like abscess or necrotizing fasciitis, and the need for prompt antimicrobial therapy. Diagnosis is primarily clinical, supported by history and physical exam findings.