Although the skin’s primary function is to protect the internal organs of the body from infection and injury, it may itself become infected. Skin infections can be caused by a fungus, bacteria, parasite, or virus. Symptoms and treatments will vary depending on the type of infection and the severity of it. Many conditions can be effectively treated at home with over-the-counter products, but some will require medical attention to resolve the problem.

Bacterial skin infections occur when bacteria get past the outer protective layer of skin (epidermis) through a hair follicle, cut, scrape, or other injury. The symptoms can range from mild to severe and will often start off with small, red bumps that begin to grow larger. Some examples of milder bacterial infections are impetigo, carbuncles, and folliculitis. More serious infections are erysipelas, cellulitis, and methicillin-resistant staphylococcus aureus (MRSA), the latter of which is difficult to treat due to its resistance to commonly used antibiotics. Various treatments may be given according to the diagnosis, but all will likely include either a topical or oral antibiotic.

Viral skin infections most commonly come from three groups of viruses: poxvirus, herpes virus, and human papilloma virus. Examples include chickenpox, shingles, warts, measles, molluscum contagiosum, and hand, foot, and mouth disease. Some viral infections will clear on their own in days to weeks without any medication. Others may require anti-viral drugs and other drugs to provide comfort and relief from symptoms.

Fungal skin infections are caused by a fungus that grows usually in moist, warm areas of the body. It often affects armpits, feet, and areas of skin that overlaps other skin. Some are contagious and some are not, and many can be treated with over-the-counter antifungal creams. Examples of fungal infection include ringworm, athlete’s foot, and oral thrush. If self-care does not clear the problem, prescription oral or topical medications may be necessary.

Parasitic skin infections occur when tiny organisms or insects burrow into the skin and lay eggs. If left untreated, infection can enter the bloodstream and affect organs within the body. Some common parasitic infections are lice, scabies, and bed bugs. These will need medicated creams to kill the parasites causing the issue.