Cellulitis: This is the most common skin infection without an abscess, characterized by redness, swelling, warmth, and pain in the affected area, usually caused by streptococcal or staphylococcal bacteria.

Erysipelas: A type of skin infection that involves the upper dermis, typically caused by group A beta-hemolytic streptococci, presenting with well-demarcated, raised, and shiny lesions.
Impetigo: A highly contagious skin infection that can present without abscesses, often caused by Staphylococcus aureus or Streptococcus pyogenes, characterized by golden-crusted lesions.
Folliculitis: An infection of the hair follicles, usually caused by Staphylococcus aureus, presenting with small, pus-filled bumps or inflamed hair follicles.

Necrotizing Fasciitis: A severe and potentially life-threatening infection that destroys the tissue under the skin, including fat and fascia, requiring immediate medical attention.
Erythema Migrans (Lyme Disease): An early manifestation of Lyme disease, presenting with a distinctive expanding rash, which is crucial to diagnose early to prevent long-term complications.
Toxic Epidermal Necrolysis (TEN) or Stevens-Johnson Syndrome (SJS): Severe skin conditions usually triggered by medications, characterized by widespread skin necrosis and detachment, which are medical emergencies.

Mycobacterial Infections (e.g., Mycobacterium marinum): Uncommon skin infections that can occur after exposure to contaminated water, presenting with lesions or ulcers.
Fungal Infections (e.g., Dermatophytosis): Infections caused by fungi, such as ringworm, which can present with various skin manifestations, including lesions and rashes.
Leptospirosis: A zoonotic infection that can cause a skin rash among other symptoms, transmitted through contact with water, food, or soil contaminated with the urine of infected animals.