What Causes Rashes?

Rashes can be caused by a variety of factors, as there are many different types of rashes. A rash can be caused by:
- Allergic reactions
- Autoimmune disease
- Genetic conditions
- Viral, bacterial, or fungal infections
- Insect bites
- Medication side effects
What Types of Rashes Are There?
There are many types of rashes. Some of the most common include:
- Dermatitis (allergic vs. irritant contact)
- Hives
- Psoriasis
- Eczema
- Insect bites
- Infections like impetigo, shingles, or ringworm
How Can I Treat Rashes?

The correct treatment for your rash will depend on its cause and associated symptoms. Oftentimes, the rash can be diagnosed on sight by your dermatologist, but sometimes additional testing such as labs or skin biopsy may be necessary to assist with the diagnosis.
Once a diagnosis has been determined, your dermatologist will recommend treatment options which may include:
- Topical medications including corticosteroids
- Light therapy
- An oral medication, such as antibiotics or steroids
- Oral antihistamines
- Other systemic medications
Rash FAQs
Are rashes dangerous?Most rashes are benign and self-limited, but some can indicate serious medical issues such as drug reactions (e.g., Stevens-Johnson syndrome), infections, or autoimmune conditions. If a rash is associated with systemic symptoms or worsens rapidly, it should be evaluated by a healthcare provider. Early intervention is key in preventing complications. Can anxiety cause a rash?Yes—stress and anxiety can trigger or worsen rashes like hives, eczema, or seborrheic dermatitis due to the body’s inflammatory response. Does heat rash spread?Heat rash, or miliaria, typically appears in areas of excessive heat and sweating, like the neck, chest, or underarms. While it doesn’t spread from person to person, new areas can become affected if overheating continues. Keeping the skin cool and dry usually resolves the rash. How can you tell if a rash is serious?A rash may be serious if it causes pain, involves mucous membranes, is accompanied by fever or fatigue, or shows signs of infection like pus or swelling. Rashes that don’t improve with over-the-counter care or that interfere with daily life should be examined. Timely evaluation can help rule out potentially dangerous conditions. How do you cure rashes?Treatment depends on the underlying cause. Allergic rashes may be treated with antihistamines or corticosteroids, while fungal or bacterial infections require targeted medications. A dermatologist can determine the correct therapy and guide you on skin care practices to prevent recurrence. Is rash contagious?Certain rashes–such as those caused by viral exanthems, bacterial infections (like impetigo), or fungal infections (like ringworm)—are contagious. In contrast, inflammatory conditions like eczema, psoriasis, or contact dermatitis are not. Proper diagnosis is essential to determine contagion risk and treatment. What are the most common skin rashes?The most frequently diagnosed rashes include eczema (atopic dermatitis), contact dermatitis, psoriasis, hives (urticaria), fungal infections like ringworm, and seborrheic dermatitis. Each has a distinct cause, pattern, and treatment. A proper dermatologic evaluation helps determine the correct diagnosis. What does an allergy rash look like?Allergic rashes often appear as red, itchy bumps, hives, or scaly patches that develop shortly after contact with a trigger. They can range from mild to severe and may include swelling or blisters in more intense reactions. Identifying and avoiding the allergen is key to management, along with appropriate medications. When should I be worried about a rash?A rash should raise concern if it’s painful, blistering, rapidly spreading, or accompanied by fever, swelling, or other systemic symptoms. Rashes that involve the eyes, mouth, or genitals should also be evaluated promptly. These signs may indicate a more serious underlying condition or infection. Will a rash go away on its own?Some rashes, such as mild irritant contact dermatitis or heat rash, may resolve without treatment once the trigger is removed. However, if a rash persists for more than a few days, becomes painful, spreads, or shows signs of infection, it's important to seek medical evaluation. |
Schedule an Appointment
Without understanding the exact type of rash you have, it is incredibly difficult to treat the rash. Schedule an appointment with a board-certified dermatologist who can diagnose your rash and establish an effective treatment plan customized to your specific situation and treatment goals.
To schedule an appointment at Arlington Dermatology, please call our office or contact us through our online form.


