A skin infection occurs when parasites, fungi, or germs such as bacteria penetrate the skin and spread. When this happens, it can cause pain, swelling, other types of discomfort, and skin color changes. A skin infection may be mild or serious.

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 infection:

  • bacterial
  • viral
  • fungal
  • parasitic

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

Cellulitis

cellulitis on skin. Image credit: Poupou l'quourouce, 2006.
Image credit: Poupou l’quourouce, 2006.

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 treatment early is important.

Symptoms

Before causing complications, cellulitis appears as swollen skin that is a different color from a person’s usual skin tone. The area is sometimes warm and tender 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 without complications. If a person does not receive treatment, cellulitis can lead to blood infections and damage the immune system.

The most typical treatment is oral antibiotics. Some people require this medication intravenously.

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

What it looks like

Cellulitis causes the affected area to swell and change color. Redness and 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.

Warts

Wart on folded skin.

According to the American Academy of Dermatology, warts are noncancerous skin growths that occur when a virus infects the top layer of skin.

Cuts and other types of skin damage put a person at risk of developing warts.

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

Symptoms

Warts are usually visible as raised areas of skin. They are much more likely to form in places where skin damage occurs, especially on the fingers, nails, and backs of the hands.

Treatment

A dermatologist can usually remove common warts. Typical techniques include:

  • cantharidin, a substance that causes a blister to form under the wart so the dermatologist can clip it off
  • electrosurgery, or burning off the wart
  • excision, or cutting the wart off
  • cryotherapy, or freezing the wart off

More difficult cases can require additional therapies, such as laser removal.

What it looks like

Warts can appear as rough areas that are the same color as the surrounding skin. They can also be darker and flat.

Herpes

Herpes around mouth and lips

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

According to the New York State Department of Health, 30–90 percent of all people are exposed to HSV-1 by adulthood, but many never develop symptoms.

After infection, a person will always have the virus in them, similar to herpes that occurs on the genitals and around the mouth. No symptoms may occur for several months or years between flares.

Though a person can treat an outbreak of herpes, the virus always remains, which means that symptoms could return at any time. The virus is also highly contagious 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:

  • swollen glands
  • fever
  • a tingling sensation in the affected area
  • lesions or blisters that last between 7 and 10 days
  • clear, fluid-filled blisters that may be painful and surrounded by a discolored patch

Treatment

Some cases of herpes require no treatment. However, a person with an active infection should avoid activities, such as sports and sex, that put them in direct contact with others.

For people with moderate to severe infections, a doctor may prescribe an antiviral medication.

What it looks like

Herpes gladiatorum manifests as a group of lesions or blisters that last between 7 and 10 days. A patch of discoloration often surrounds these clear, fluid-filled blisters.

Yeast

Yeast infection

A yeast infection develops when fungus grows out of control.

Yeast infections can occur in various parts of the body, but they are more common in areas that trap moisture.

The vagina is particularly susceptible to yeast infections such as thrush, which can also occur in the mouth and is often a symptom of a weakened immune system.

Yeast infections can develop on the skin, and two commonly known examples are diaper rash and athlete’s foot.

Symptoms

The most common symptoms of a yeast infection include a rash and itchiness. Some yeast infections can cause blisters or pustules.

Treatment

Yeast infections on the skin may respond to treatment at home with creams and ointments. Many options are available over the counter.

However, some yeast infections on the skin may require prescription medication and creams.

Anyone with a yeast infection on the skin should keep the area clean and dry. When dealing with diaper rash, change the diapers frequently.

What it looks like

Yeast infections appear differently in different areas of the body.

For example, a diaper rash that results from a yeast infection looks like areas of chafed, differently colored skin.

Yeast infections elsewhere on the skin may appear as areas of small, raised blisters or pustules.

Lice

Lice in hair.

Lice, or head 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 clean or dirty hair.

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 types of skin infection, itchiness is the most common symptom. Typically, it develops around the ears and near the neck.

According to the American Academy of Pediatrics (AAP), it can take 4–6 weeks for a person to become sensitive to lice saliva and for the itchiness to start.

Even after treatment, several weeks may pass before this feeling goes away.

Treatment

A person can treat head lice at home, but speak to a doctor 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.

A range of lice combs is available to purchase online.

It is important to follow the doctor’s instructions before treating lice.

What it looks like

Lice look different, depending on their stage of life.

Nits, or eggs, are very tiny. A person may initially confuse nits with dandruff because of the close resemblance.

When the eggs hatch, the lice are called nymphs. In this stage, a person may notice small, fast-moving mites in their scalp.

Adult lice are about the size of sesame seeds and light gray or tan. Each bug has six clawed legs.

Scabies

Scabies on hand skin

Scabies is another parasitic skin infection.

When a person has scabies, tiny mites burrow into the upper layer of skin to lay their eggs. An infestation affects the outer layers of the skin.

According to the Centers for Disease Control and Prevention (CDC), scabies is present worldwide, and the skin infection can affect all types of people.

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

Symptoms

When infected with scabies, the most common symptoms are:

  • intense itchiness
  • a pimple-like rash

In addition, a person may experience:

  • tiny blisters and scales
  • burrows in the skin
  • skin sores, from scratching the rash

The rash can appear nearly anywhere on the body. Some of the most common sites include the:

  • elbows
  • armpits
  • wrist
  • penis
  • webbing between the fingers
  • nipples
  • waist or beltline
  • 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 by prescription.

Since scabies is very easy to contract, people typically administer treatment to sexual partners and household members as well. To prevent spreading, it is best for everyone to receive treatment at the same time.

Also, it is important to keep the living environment clean and to wash and bag clothing and bedding for 2–3 weeks.

What it looks like

Scabies causes a pink, pimple-like rash that may contain small blisters and areas of scaling. Additionally, a person with scabies may notice burrows in the skin.

The infection is most likely to appear on the hands or feet.

When to see a doctor

Seek medical advice anytime an unexplained, persistent rash appears on the 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 medication or other forms of treatment.

Prevention

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. Avoiding physical contact with people who have scabies or an active herpes infection can prevent exposure. It is also important to care for wounds carefully.

People with skin infections should take precautions and avoid physical contact until symptoms clear up or they receive the go-ahead from their doctor.

Takeaway

Skin infections are a very common occurrence throughout the world. Anyone is at risk, and these infections can spread easily. It is important to take precautions.

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