What causes a rash on the stomach? Related conditions and treatments

Overview: What does a rash on the stomach look like?

A stomach rash can be caused by various conditions, from harmless skin reactions to serious infections. What the rash looks like is one clue to possible causes. A stomach rash could be confined to one area of the stomach or spread all over the body. It might be a bunch of spots or a solid red area. The color can vary widely from bright red to purple and brown to pale. The skin could be flat, raised, bumpy, or look like blisters or sores. Other aspects of the rash, like itchy skin, tingling, pain, swelling, flakiness, or oozing fluid, are also clues. The full picture often comes into light when other symptoms are factored in.

What causes a rash on the stomach?

There are many reasons a rash appears on the belly. Some are harmless, but a stomach rash could also point to an infection or an allergic reaction.

Contact dermatitis

People may develop rashes when the skin comes in contact with irritants, allergens, or poisons. The rash is a reaction to that irritant. It’s often accompanied by itchiness or swelling. The most common causes include:

• Insect bites or stings

• Poison ivy or poison oak

• Chemicals

• Common household items like soap, shaving lotion, shampoo, dye, or detergent

RELATED: How to treat contact dermatitis

Eczema

Eczema (atopic dermatitis) is a common dry skin condition that can turn into an itchy rash. Like contact dermatitis, it can be triggered by skin irritants. However, it can also be triggered by stress, hormones, foods, climate, and even allergic reactions elsewhere in the body.

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Hives

Hives (urticaria) are an immune system reaction that lasts for a few hours or days. They usually consist of raised welts and redness. Like contact dermatitis, hives can break out when something touches or enters the skin. However, they can also occur because of food allergies, inhaled allergens, and stress or exercise. 

Heat rash

Heat rash is provoked by exercise or heat. It can break out anywhere on the skin and looks like a cluster of tiny, swollen spots. The rash itself is caused by sweat gland blockage. 

Pregnancy

During pregnancy, women may develop a swollen, itchy, and harmless rash on the abdomen, especially along stretch marks. The rash usually appears in the last trimester of pregnancy. Called pruritic urticarial papules and plaques of pregnancy (PUPPP), the rash typically goes away after delivery. It is more common with first pregnancies. 

Infections

A stomach rash may also be a sign of certain bacterial or viral infections:

• Measles: Measles is a viral infection. It occurs most commonly in children who have not been vaccinated against measles. The rash begins on the face or head and quickly spreads to the neck, chest, back, stomach, arms, and legs. Other symptoms include a high fever, cough, and red, watery eyes. 

• Chickenpox: Chickenpox is also caused by a virus. It occurs in children who have not received the varicella vaccine. Chickenpox rash affects the face, chest, shoulders, stomach, and back.

• Fifth disease: Another viral childhood disease, fifth disease (parvovirus), has distinctive rash symptoms, including red cheeks and a lace-like rash on the arms and thighs. About half of children with the infection will also develop a rash on the chest and stomach.

• Scarlet fever: Scarlet fever is a bacterial infection caused by the same group of bacteria that causes strep throat. The infection usually affects children but can also occur in adults. A scarlet fever rash can cover the entire body in a rough, red rash that feels like sandpaper. Other symptoms include fever, sore throat, headache, and tongue color changes. 

• Impetigo: A childhood skin infection caused by bacteria, an impetigo rash typically appears on the face but can erupt anywhere on the body. The rash is composed of red, blister-like nodules that may ooze fluid. 

• Pityriasis rosea: Despite its difficult name, pityriasis rosea is a very common rash caused by a virus. The rash usually begins on the chest, stomach, or face, starting as a large, pale, scaly patch. Later, this patch is surrounded by a rash of smaller pale or light red spots.

• Shingles: Shingles is a potentially serious reactivation of the chickenpox virus. It occurs most often in older adults. The infection affects just one part of the skin, causing a tingling, painful, dense rash of red nodules on the affected area. 

• Ringworm: Ringworm, or tinea corporis, is a fungal skin infection similar to athlete’s foot. It can look like a single ring-shaped patch, a group of smaller ring-shaped patches, or a red rash.

• Lyme disease: Lyme disease is a bacterial infection spread through tick bites. The waist and stomach are two of the most common places on the human body where tick bites are found. The earliest sign of a Lyme infection is a bullseye rash that radiates and expands from the bite location. 

• Rocky Mountain spotted fever (RMSF): Another bacterial infection spread by tick bites, RMSF is a potentially life-threatening disease that can produce a rash anywhere on the body as a later symptom of the infection. Earlier symptoms include fever, nausea, and headache.

• Scabies: Scabies is caused by an infestation of tiny bug-like creatures called mites. A scabies rash is caused by multiple scabies bugs burrowing under the skin. The rash looks like a cluster of pimples. A scabies rash is intensely itchy.

Blood vessel problems

A red rash on the stomach may be caused by blood vessel damage due to autoimmune diseases, heavy lifting, skin damage, or benign reasons:

• Vasculitis is a potentially serious autoimmune flare-up that causes blood vessel swelling.

• Angiomas are benign growths of the capillaries near the surface of the skin.

• Petechiae are tiny dots that appear when tiny blood vessels burst beneath the surface of the skin.

• Kawasaki disease is a severe childhood condition that causes blood vessels to swell, causing a rash on the trunk and other areas of the body. Other symptoms include red eyes, red palms, red soles, high fever, and abdominal pain.

Drug rashes

Some prescription medications may produce a skin rash as a side effect. Drug rashes vary in appearance and severity. Some have the potential to become severe and life-threatening conditions. 

Other skin problems

Other conditions that may cause a rash on the stomach include:

• Folliculitis is a cluster of swollen hair follicles. They often appear as brownish-red bumps.

• Keratosis pilaris is a common, harmless condition that causes a rash of red bumps or patches on one skin area.

• Psoriasis is an autoimmune condition that causes scaly, swollen rashes on one or more areas of the skin.

• Lichen planus is an immune system reaction that causes an itchy, bumpy, and purple rash on the wrists, hands, or legs. It can affect the stomach as well.

RELATED: What are the early signs of psoriasis?

Should I be worried about a rash on the stomach?

If a rash develops on the skin and there isn’t an immediate explanation for it, such as poison ivy or bug stings, then get medical advice from a healthcare provider. If there are other symptoms or the rash isn’t improving, make an appointment to see a provider. Many possible causes of stomach rash require treatment or monitoring. 

Get immediate medical help if, in addition to the skin rash, there are symptoms such as a purple rash, high fever, rapidly worsening skin symptoms, difficulty breathing, difficulty swallowing, swelling of the face (or lips or mouth), throat constriction, lightheadedness, confusion, or racing heartbeats.

How is the cause of a rash on the stomach diagnosed?

A healthcare professional will begin a diagnosis by examining the rash, reviewing other symptoms, and taking a medical history. Some tests, such as a blood test or a biopsy, may be needed, depending on the suspected cause. It may be necessary for the provider to refer to a specialist such as an allergist, dermatologist, or rheumatologist. Other tests, such as allergy tests, blood tests, medical imaging, or a biopsy, may be needed in those cases. 

Is a rash on the stomach contagious?

Most infections that cause stomach rash are contagious and can be spread either through contact or respiratory droplets. A few infections, such as tick-borne diseases, cannot be spread from person to person.

How long does a rash on the stomach last?

A stomach rash could last a few hours in the case of an allergic reaction. Or it could be a chronic or recurring condition like keratosis pilaris or psoriasis. It will depend on the underlying cause of the rash and how the body responds to it. 

Stomach rashes due to infections are usually limited in duration. They resolve on their own as the body fights off the infection or with antimicrobial treatment.

How to stop a rash on the stomach

To get rid of a rash on the stomach, healthcare providers treat the underlying cause.

Contact dermatitis and heat rash are usually treated with over-the-counter remedies such as calamine lotion, anti-itch creams, and oral antihistamines. Cold compresses can also help calm a heat rash. 

For eczema, the usual treatment options involve gentle cleansing of the affected area, moisturizing lotions or ointments, and over-the-counter or prescription corticosteroid anti-itch creams.

Infections are treated with antimicrobial drugs when needed and symptom-relief medications. 

Other causes of stomach rash may involve more complicated treatments such as immunosuppressants or other therapies.

What’s next? Additional resources for people with a rash on the stomach

Test and diagnostics

• Atopic dermatitis: diagnosis and treatment, American Family Physician

• The generalized rash part I: differential diagnosis, American Family Physician

Treatments

• Eczema treatments and medications, SingleCare

• Heat rash treatments and medications, SingleCare

• Hives treatments and medications, SingleCare

• How to treat contact dermatitis, SingleCare

• Keratosis pilaris treatments and medications, SingleCare

Scientific studies and clinical trials

• Where ticks bite: check your thigh first, Upstate survey indicates, Upstate Medical University

More information on related health conditions

• Allergies treatments and medications, SingleCare

• Herpes treatments and medications, SingleCare

• Psoriasis treatments and medications, SingleCare

• Ringworm treatments and medications, SingleCare

• Scabies treatments and medications, SingleCare