A skin infection occurs when parasites, fungi, or germs such as bacteria penetrate the skin and spread. This can cause pain, swelling, and skin color changes.

Skin infections are different from rashes. A rash is an area of swollen or irritated skin. While rashes can be symptoms of some skin infections, a person with a rash does not necessarily have an infection.

There are four types of skin infections:

  • bacterial
  • viral
  • fungal
  • parasitic

Some skin infections require medical treatment. People can manage others with over-the-counter (OTC) solutions or home remedies. Read on to learn more about common skin infections.

This common bacterial skin infection occurs when bacteria infect the deep layers of skin and nearby tissues.

According to the American Academy of Dermatology, doctors diagnose 14.5 million cases of cellulitis in the United States each year.

Cellulitis can lead to serious complications, and receiving early treatment is important.

Symptoms

Cellulitis causes the affected area to swell and change color. On lighter skin, cellulitis may appear red or pink, while on darker skin tones, it may appear purple, brown, or darker than the surrounding area.

Other skin changes may not be well-defined, and it may be difficult to tell where they end. The area will likely be hard and warm to the touch.

Cellulitis can develop anywhere on the body. In children, it commonly affects the face, and in adults, it often appears on the lower legs.

Treatment

Early treatment is key to a successful outcome. If a person does not receive treatment, cellulitis can lead to blood infections and damage the immune system.

The standard treatment is oral antibiotics. Some people may need to take this medication intravenously.

A person should also rest, elevate the affected area, and cover the area to aid healing.

Warts are noncancerous skin growths that occur when a virus infects the top layer of skin.

Warts are transmissible. A person can get them by touching a wart directly or coming into contact with something the wart has touched.

Symptoms

The exact appearance of a wart may depend on the type a person has. Below are some examples:

  • Common warts: Common warts can be as large as a pea. They typically affect the hands, fingers, and feet. They may be scaly and hard to the touch.
  • Plantar warts: Plantar warts, or verrucas, usually affect the feet and ankles, and can vary in size. If they are on the bottom of the feet, they may invert from the pressure of walking, which can cause discomfort and pain.
  • Mosaic warts: Mosaic warts typically affect the toes and soles of someone’s feet, but they are flatter than plantar warts. They are typically white and no larger than the size of a pinhead.
  • Flat warts: Flat warts typically affect the face, hands, and lower arms. They usually grow to be a few millimeters (mm) wide and will be slightly raised and light brown.
  • Filiform warts: Filiform warts typically affect the face. They have a thread-like, spike appearance that may make them look like brushes.
  • Genital warts: Genital warts only affect the genital area. They have rough surfaces and are small and firm.

Treatment

Around 2 in 3 warts will go away by themselves within two years. However, some warts may grow or spread to other areas without treatment.

Treatments for warts may include:

  • salicylic acid, which a person can use at home without a prescription
  • cryotherapy — freezing the wart off
  • retinoic acid or tretinoin, a topical cream
  • podophyllin, a topical treatment that stops tissue growth
  • topical 5-fluorouracil, a topical cream or solution
  • interferon, an injection
  • imiquimod, a prescription cream
  • burning off the wart
  • excision — cutting the wart off

The most suitable treatment may vary depending on the type of wart.

The herpes simplex virus type 1 (HSV-1) is responsible for causing a herpes gladiatorum infection on the skin.

According to the World Health Organization, around 64% or 3.8 billion people worldwide under 50 years old have HSV-1 infection.

Though a person can treat an outbreak of herpes, the virus always remains, which means symptoms can return at any time. The virus is also highly infectious, and a person can transmit it any time it is active, even if no symptoms are present.

Symptoms

When herpes gladiatorum flares, it can cause:

Treatment

Doctors may prescribe antiviral medications to manage a person’s symptoms. The following types may help to reduce the severity and duration of symptoms:

They may also recommend that a person take over-the-counter (OTC) pain relief if they experience any pain from HSV-1 sores.

A yeast infection develops when a fungus grows out of control. Yeast infections can occur across the body, particularly in areas where the skin folds on itself, such as the armpits, groin, and between the fingers.

Yeast infections are also common in other areas that trap moisture, such as the vagina and mouth.

Symptoms

Symptoms of a yeast infection include the formation of a rash and localized itchiness. Some yeast infections can cause blisters or pustules.

Yeast infections appear differently in different areas of the body. For example, a diaper rash that results from a yeast infection may appear as areas of chafed, differently colored skin and not feature any blisters.

Treatment

A person may be able to treat a yeast infection with OTC antifungal creams and ointments. Some yeast infections on the skin may require prescription medication and creams.

Anyone with a yeast infection on the skin should keep the area as clean and dry as possible while the infection resolves.

Lice are tiny insects that live in hair and cause a parasitic infection of the scalp. They exist worldwide and can affect anyone. Contrary to popular belief, lice can live in any type of hair, regardless of how often a person washes it.

Lice spread easily, especially in crowded conditions such as schools and nursing homes. Though a nuisance, lice do not cause serious health issues.

Symptoms

As with many other skin infections, itchiness is the most common symptom of lice. It can take 4 to 6 weeks for the itchiness to start. Even after treatment, several weeks may pass before this feeling goes away.

A person may be able to see lice in their hair. Nits, or eggs, are small and attach at the base of hairs. People may initially confuse nits with dandruff.

When the eggs hatch, the lice are called nymphs. In this stage, a person may notice small, fast-moving mites on their scalp. Adult lice are about the size of sesame seeds and are light gray or tan.

Treatment

A person can treat lice at home but should speak with a healthcare professional before doing so.

Treatment typically involves combing the lice and their eggs out of the hair and applying medication that kills the lice and their eggs.

Scabies is another parasitic skin infection. When a person has scabies, mites burrow into the upper layer of skin to lay their eggs, causing infection and irritation.

Scabies spreads through prolonged skin-to-skin contact. People living in crowded conditions, such as nursing homes, are most likely to experience outbreaks.

Symptoms

Scabies causes a pimple-like rash that may contain small blisters and areas of scaling. These rashes may appear red or pink on light skin and brown or black on darker skin.

People with scabies may notice burrows in the skin, and small sores and scales. These skin complaints may cause irritation and feel itchy.

Rashes from scabies can appear nearly anywhere on the body. Some of the most common sites include the:

  • elbows
  • armpits
  • wrists
  • penis
  • between the fingers
  • nipples
  • waist
  • buttocks

Treatment

Scabies treatment involves medications called scabicides. These kill adult mites, and some also kill the eggs. Tested and approved scabicides are only available on prescription.

Since scabies can spread quickly within households and other indoor settings, close contacts of a person with scabies may also require medication.

A person should seek medical advice anytime an unexplained, persistent rash appears on their body.

It is especially important to contact a doctor if the rash occurs alongside a fever or symptoms other than itchiness or pain. Many skin infections require prescription medication or other forms of treatment.

Since many skin infections are easy to contract, people should use caution in public areas.

For example, wearing shoes in public bathrooms and showers can help prevent athlete’s foot, which is a common fungal infection. Avoiding physical contact with people who have scabies or an active herpes infection can help prevent exposure.

People with skin infections should take precautions and avoid physical contact until symptoms are gone or their doctor clears them to do so.

Skin infections are a common occurrence worldwide. These infections can spread easily through physical contact and can affect almost anyone.

Most infections present as rashes or small growths and typically cause irritation and itchiness. Affected areas of skin may appear pink or red on people with light skin or brown and black on people with darker skin.

If an unexplained rash appears, seek medical attention as soon as possible.