Published: 18 Jun 2025

ICD9: 686.9      ICD10: L08.9      ICD11: EA5Z

A skin infection is an infection that affects the skin.
They are incredibly common and can be caused by a variety of pathogens, including:

Bacteria: (e.g., *Staphylococcus* and *Streptococcus*)
Fungi: (e.g., dermatophytes, yeast)
Viruses: (e.g., herpes simplex virus, varicella-zoster virus)
Parasites: (e.g., mites, lice)

The term "skin infection" covers a *broad* range of conditions. Common examples include:

Bacterial Infections:
Cellulitis: A deep infection of the skin and underlying tissues, often caused by bacteria entering through a break in the skin.
Impetigo: A superficial skin infection, common in children, characterized by honey-colored crusts.
Folliculitis: An infection of hair follicles.
Boils (Furuncles) and Carbuncles: Deeper infections involving hair follicles and surrounding tissue.
Fungal Infections:
Athlete's Foot (Tinea Pedis): Affects the feet.
Ringworm (Tinea Corporis): Can affect various parts of the body (despite the name, it's not caused by a worm).
Jock Itch (Tinea Cruris): Affects the groin area.
Yeast Infections (Candidiasis): Can affect skin folds, mucous membranes (e.g., mouth - thrush, vagina - vaginal yeast infection), and other areas.
Viral Infections:
Cold Sores (Herpes Simplex Virus): Usually around the mouth.
Chickenpox and Shingles (Varicella-Zoster Virus): Chickenpox is the initial infection, and shingles is a reactivation of the virus.
Warts (Human Papillomavirus - HPV):
Parasitic Infections:
Scabies: Caused by mites burrowing into the skin.
Lice (Pediculosis): Head lice, body lice, pubic lice.

Symptoms of Skin Infections:

Symptoms vary depending on the type of infection, but common signs include:

Redness: The affected area of skin may be red or inflamed.
Swelling: The skin might be swollen or puffy.
Pain or Tenderness: The infected area may be painful to the touch.
Itching: Itching is a common symptom, especially with fungal and parasitic infections.
Pus-filled Blisters or Sores: These can indicate a bacterial infection.
Rash: Various types of rashes can occur, depending on the cause.
Warmth: The affected area may feel warmer than surrounding skin.
Fever: In more severe cases, a fever may be present.

Diagnosis:

A doctor can usually diagnose a skin infection by examining the affected area. Sometimes, they may take a sample of skin, pus, or fluid for testing (e.g., culture, microscopic examination).

Treatment:

Treatment depends entirely on the type of infection:

Bacterial Infections: Treated with topical or oral antibiotics.
Fungal Infections: Treated with topical or oral antifungal medications.
Viral Infections: Some viral infections resolve on their own. Antiviral medications may be used for more severe cases.
Parasitic Infections: Treated with topical or oral antiparasitic medications.

Prevention:

Good Hygiene: Wash hands frequently, especially after touching potentially contaminated surfaces.
Keep Skin Clean and Dry: Especially in areas prone to fungal infections (e.g., feet, groin).
Avoid Sharing Personal Items: Such as towels, razors, and clothing.
Avoid Touching Infected Areas: If you have a skin infection, avoid touching it and wash your hands thoroughly if you do.
Proper Wound Care: Clean and cover any cuts or scrapes to prevent infection.
Wear Appropriate Footwear: In public showers and locker rooms to prevent athlete's foot.

When to See a Doctor:

It's important to see a doctor if:

The infection is severe or spreading rapidly.
You have a fever.
The area is very painful.
Home treatment is not working.
You have a weakened immune system (e.g., due to diabetes, HIV/AIDS, or medications).
You are concerned about the infection.

In summary, a skin infection is an invasion of the skin by a pathogen. The type of pathogen determines the specific infection and its treatment. Proper hygiene and prompt medical attention are important for managing and preventing skin infections.