Common Rashes That Look Like Mosquito Bites

Updated October 31, 2022
Rash on neck

If you're a parent, you know that it's not unusual for young children to get a rash that sends them to the doctor. Adults can also be affected by rashes, which are often caused by skin conditions such as eczema, allergic reactions to environmental allergens, bug bites, or bacterial, fungal, and viral infections.

Sometimes, rashes look like mosquito bites. Identifying the possible cause of a rash that resembles mosquito bites can be challenging because itchy, red bumps on the skin can have numerous possible causes.

Rashes That Might Look Like a Mosquito Bite

A rash is an area of skin that is irritated, inflamed, and/or swollen. The lining of the skin contains numerous mast cells, which are designed to protect the body against bacteria and parasites. These cells contain chemicals called histamine. When a person is exposed to an allergen (such as pollen, bee stings, foods, latex, certain chemicals), the body releases histamines in response. Once the histamine is released into the bloodstream, it can accumulate in the skin and cause a visible rash with swelling, irritation, and itchiness.

When you discover a rash on your body (or your child's body), it's important to closely study the rash. To the untrained eye, many rashes look the same. Before you talk to your healthcare provider, take note of how long you've had the rash, the part of the body affected by the rash, the size of the rash, and whether or not it itches. These details can help you identify the possible cause. You may find that the rash is one of these skin conditions.

Hives

Hives

Hives (urticaria) are a condition that looks like raised, itchy bumps on the skin that can appear similar to mosquito bites. If you notice itchy bumps on your skin but know you haven't been exposed to mosquitos, you may have hives.

What they look like: Hives are smooth, raised, and pink to reddish bumps or wheals that can range in size. They may appear ring-shaped, oval-shaped, or circular with a pale center and red halo or flare in the outer rim. Characterized by blanching, the redness of the bumps may go away and turn pale when pressed on. Wheals (welts) may disappear quickly and be replaced by newly formed ones. In general, hives appear in clusters, covering part or all of the body. They are often accompanied by intense itching.

What causes them: According to the American Academy of Allergy Asthma & Immunology, skin allergies that lead to hives are often attributed to medication and food allergies. Exposures to allergens such as pollen, pet dander, or seafood very commonly result in hives. Other causes of hives include:

  • Infections: Several bacterial and viral infections, including tooth decay, may cause hives to develop.
  • Low temperatures: Cold temperatures can sometimes cause hives within minutes of exposure to the cold. Even very cold swimming pools or consuming cold foods can trigger hives in some people.
  • Stress: Stress causes the body to release cortisol (stress hormone), which is associated with chronic hives in some people.
  • Sunlight and heat: Although rare, some people develop hives after exposure to the sun. This can occur if you've been indoors throughout winter and spend time in the sun when it finally warms up. Hives may also appear on parts of the body that are rarely exposed to the sun if left uncovered while outside.
  • Working out or exercise: The increase in body temperature and subsequent sweat may cause hives.

Home remedies: If you know what caused your allergic reaction and subsequent hives, avoid future exposure to the allergen. Other methods to treat hives at home include:

  • Apply an ice pack over the rash to relieve inflammation and itching.
  • Cool oatmeal baths to soothe itchy, irritated skin.
  • Cut your nails short to avoid scratching the rashes and breaking the skin, which can increase the risk of infection.
  • Over-the-counter medications, such as antihistamines, can help block the release of histamine and provide relief from hives, according to the American Academy of Dermatology.
  • Wear loose-fitting clothing to prevent further irritation to the affected skin.

When to see a doctor: If home remedies do not provide relief from hives, see your healthcare provider. They may perform allergy testing or prescribe a medication such as an antihistamine to clear the rash. Seek emergency care if you have hives with additional symptoms, such as swollen lips and trouble breathing.

Heat Rash (Miliaria)

Heat rash

Miliaria, or heat rash, is a skin condition triggered by blocked sweat glands and ducts.

What it looks like: Also called "prickly heat," miliaria is characterized by a rash with clear, fluid-filled bumps on the skin that do not itch or hurt. It is commonly seen in areas of the body where sweat can get trapped, such as the neck, upper chest, or elbow creases.

What causes it: Miliaria is primarily caused by clogged sweat ducts during the summer season or hot temperatures. It is most common in warm, humid areas during the summer months. An overdressed baby who spends time in the hot summer sun may develop a heat rash. Heavy cream use may contribute to pore blockages, which can lead to heat rash if a person sweats while working out or spending time outside under the sun.

Home remedies: Heat rashes typically disappear after a couple of days of air drying and keeping cool. Home remedies for heat rash include:

  • Aloe vera applied topically to the skin
  • Avoid humidity and excessive sweating by spending time in an air-conditioned home
  • Cool showers or baths
  • Ice packs or cold cloths placed on the rash to reduce swelling and inflammation
  • Light, loose clothing
  • Oatmeal baths

When to see a doctor: If your heat rash gets worse instead of better over the course of three to four days, see your healthcare provider. Seek immediate medical attention for severe itchiness or a rash with pus-filled blisters.

Contact Dermatitis

Dermatitis

Contact dermatitis can occur after exposure to an irritant substance and may sometimes look like a mosquito bite.

What it looks like: The appearance of contact dermatitis can depend on the allergen that caused the allergic reaction. The rash can develop within minutes after exposure or take up to 1-2 days to develop. Contact dermatitis may look like leathery, dark patches of skin, bumps, and blisters that are oozing or crusted, or dry, cracked skin. Contact dermatitis is often itchy and accompanied by swelling, burning, and tenderness.

What causes it: Contact dermatitis occurs when the skin is exposed to a known irritant, such as detergents, perfumes, cosmetics, soaps, metal jewelry, deodorant, or other known allergens.

Home remedies: Home remedies for contact dermatitis can include:

  • Cool bath or shower
  • Avoid the irritant/allergen
  • Apply cool, wet compresses to the affected area

It may take 3-4 weeks for contact dermatitis to clear up completely.

When to see a doctor: See your healthcare provider for contact dermatitis if your rash is so itchy you cannot sleep or do your daily activities, the rash is severe and/or widespread, the rash affects your eyes, mouth or genitals, or if the rash does not get better after three weeks.

Skin rashes that look like mosquito bites can range from mild to severe. If you have trouble identifying the cause of your mosquito bite-like rash, talk to your healthcare provider. They can examine your rash and determine the appropriate course of treatment.

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Common Rashes That Look Like Mosquito Bites