Last summer, my daughter came home from swim camp with red, scaly patches between her toes. I assumed it was just irritation from wet flip-flops. Two weeks later, when the patches spread to her ankles and started cracking, I finally took her to the pediatrician. Athlete’s foot. A fungal infection. I’d been treating it like dry skin with lotion, which actually made it worse by creating more moisture for the fungus to thrive.
That experience taught me that not all skin problems are simple rashes or irritation. Skin infections come from entirely different sources, require different treatments, and can get worse if you misidentify them. Understanding the five main types of skin infections helps you recognize what you’re dealing with and seek appropriate treatment before minor issues become major problems.
Table of Contents
The Five Main Categories of Skin Infections
Skin infections occur when harmful microorganisms invade your skin and multiply. These infections fall into five distinct categories based on what causes them: bacterial infections, viral infections, fungal infections, parasitic infections, and less common atypical infections.
Each category involves different organisms, appears differently on the skin, spreads through different mechanisms, and responds to completely different treatments. What works for a bacterial infection won’t touch a fungal infection, and vice versa. This is why proper identification matters so much.
Bacterial Skin Infections
Bacterial skin infections develop when bacteria enter your skin through cuts, scrapes, insect bites, or damaged areas. The most common culprits are Staphylococcus aureus and Streptococcus bacteria.
Common bacterial infections include
Cellulitis is a deep skin infection affecting deeper layers of skin and underlying tissue. It appears as red, swollen, warm, tender skin that spreads rapidly. Cellulitis most commonly affects legs but can occur anywhere. About 14.5 million cases are diagnosed annually in the United States. Left untreated, cellulitis can spread to lymph nodes and bloodstream, becoming life-threatening.
Impetigo is highly contagious and common in children. It creates red sores that rupture, ooze, and develop honey-colored crusts. Impetigo usually appears around the nose and mouth but can spread to other areas through scratching. It spreads easily in schools and daycare settings.
Folliculitis is infection of hair follicles creating small red bumps or white-headed pimples around hair follicles. It commonly appears after shaving, wearing tight clothing, or soaking in poorly maintained hot tubs. Most cases are mild and clear on their own.
Boils are painful, pus-filled bumps forming under skin when bacteria infect and inflame hair follicles. They start small and can grow to golf ball size. Boils are extremely tender and may require drainage by a doctor.
Treatment
Most bacterial infections require antibiotics, either topical creams for mild cases or oral antibiotics for more serious infections. Some resistant bacteria like MRSA need stronger antibiotics and careful monitoring.
My coworker developed cellulitis on her shin after a small cut she ignored. Within 48 hours, the redness spread from her ankle to knee. She needed IV antibiotics in the hospital for three days. That experience made me much more careful about cleaning and monitoring even minor skin wounds.
Viral Skin Infections
Viral skin infections are caused by viruses and tend to be extremely contagious.
Common viral infections include
Herpes simplex causes cold sores around the mouth or genital herpes. These appear as painful fluid-filled blisters that crust over. The virus remains dormant and can reactivate during stress or illness.
Shingles creates a painful stripe of blisters on one side of the body, typically the torso or face. Most common in people over 50 or those with weakened immunity.
Warts are caused by HPV and appear as small, rough bumps on hands, feet, or other areas. They’re harmless but contagious.
Molluscum contagiosum creates small, flesh-colored bumps with a dimple in the center. Extremely common in children.
Treatment
Some resolve on their own. Others require antiviral medications. Warts can be frozen or burned off. Prevention focuses on avoiding contact with infected individuals.
I had shingles at 38. The pain was intense, like someone had taken a blowtorch to my ribcage. Antiviral medication helped, but nerve pain lasted months.
Fungal Skin Infections
Fungal infections thrive in warm, moist environments where skin surfaces meet or moisture accumulates.
Common fungal infections include
Athlete’s foot causes itching, burning, cracking, and scaling between toes and on soles. It spreads easily in locker rooms and pools. Ringworm creates circular, red, scaly patches with raised edges. It can appear anywhere and is highly contagious.
Jock itch affects the groin and inner thighs, creating red, itchy, ring-shaped rashes. More common in men and heavy sweaters.
Yeast infections create red, itchy rashes in skin folds, mouth, or genital areas. Nail fungus makes nails thick, discolored, and brittle, requiring months of treatment.
Treatment
Antifungal creams, powders, or sprays treat most cases. Severe infections may require oral medications. Prevention involves keeping skin clean and dry.
After my daughter’s athlete’s foot, I’m obsessive about drying between toes after swimming and using antifungal powder in shoes.
Parasitic Skin Infections
Parasitic infections occur when parasites live on or in your skin, feeding on blood or laying eggs. These infections cause intense itching and can spread rapidly through close contact.
Common parasitic infections include
Scabies is caused by tiny mites that burrow into the upper layer of skin to lay eggs. It creates intense itching that worsens at night and small red bumps or blisters. Scabies spreads through prolonged skin-to-skin contact and is common in crowded living situations.
Head lice are tiny insects that live in hair and feed on blood from the scalp. They cause intense itching and are extremely common in school-age children. Lice spread through head-to-head contact or sharing hats, combs, or bedding.
Body lice live in clothing and move to skin to feed. They’re less common than head lice and typically affect people who can’t regularly bathe or launder clothing.
Treatment
Parasitic infections require specific medications called scabicides for scabies or pediculicides for lice. These are available by prescription or over the counter depending on the product. Treatment often requires treating all household members simultaneously and washing all bedding and clothing in hot water.
My son came home with head lice from kindergarten three times in one year. The treatment process was exhausting. Special shampoo, combing out nits for hours, washing every piece of fabric in the house, bagging stuffed animals for two weeks. Lice don’t indicate poor hygiene, but they’re still a nightmare to eliminate.
Less Common Atypical Infections
Beyond the four main categories, some skin infections don’t fit neatly into bacterial, viral, fungal, or parasitic classifications. These atypical infections include conditions caused by unusual organisms or environmental factors.
Rickettsial infections like Rocky Mountain spotted fever and typhus cause distinctive rashes along with systemic symptoms. These are transmitted by ticks, fleas, or mites.
Mycobacterial infections include conditions like leprosy (Hansen’s disease) or infections from atypical mycobacteria found in soil and water.
These infections are relatively rare but require specialized treatment and often involve infectious disease specialists.
How to Know Which Type You Have
Identifying the infection type yourself can be difficult because symptoms sometimes overlap. However, certain clues help narrow possibilities.
Bacterial infections typically feature swelling, warmth, redness, pain, and pus or drainage. They often develop rapidly over hours to days.
Viral infections may include blisters filled with clear fluid, systemic symptoms like fever, and lesions that crust over.
Fungal infections create scaly, itchy patches often with defined borders. They develop slowly and worsen in warm, moist conditions.
Parasitic infections cause intense itching, visible movement or organisms, and small burrows or trails in the skin.
When in doubt, see a doctor. Dermatologists can often diagnose infections visually, but they may take skin scrapings, cultures, or biopsies to confirm the specific organism and prescribe appropriate treatment.
Conclusion
The five types of skin infections are bacterial, viral, fungal, parasitic, and atypical infections. Each category has distinct causes, appearances, transmission methods, and required treatments.
Most skin infections are treatable when caught early. However, misidentifying the infection type can lead to ineffective treatment and worsening conditions. What helps a bacterial infection won’t work for fungal infections, and treating fungus with bacteria medication wastes time and money.
