When a rash appears on our skin, often our first reaction is to buy some over-the-counter cream and wait for it to disappear.

There are times when that’s not the best approach.

Rashes are caused by a number of things, from allergies to viruses. Depending on the rash and its accompanying symptoms, you could need medical help to clear it up.

Some things that can cause a rash include:

• Skin contact with something you’re allergic to
• Food or drug allergies
• Viruses (such as hand foot mouth disease or chickenpox)
• Fungus and bacteria
• Bug bites

Depending on the cause, the appearance of the rash can vary. Some rashes are dry and itchy, others are blotchy or form large hives.

Over-the-counter hydrocortisone cream will usually ease symptoms of rashes caused by allergies, such as poison ivy or poison oak. Sometimes, a poison ivy outbreak can require further medical attention.

See your primary care doctor or a dermatologist if your rash comes with:

• Joint pain
• A sore throat
• A fever slightly above 100.4°F (38°C). Fevers with a rash could indicate a disease such as measles, shingles or scarlet fever.
• Red streaks or tender areas near the rash
• A recent tick bite or other insect bite. Ticks can transmit Lyme disease, which can cause a bullseye-shaped rash, among other symptoms.
• Swelling of the tongue and/or lips, vomiting or trouble breathing. This can indicate a severe, life-threatening allergic reaction and requires immediate medical attention.

Also see a doctor if:

• The rash hurts.
• The rash is all over your body.
• The rash appears suddenly and spreads quickly. This can happen with a severe allergic reaction, which requires immediate medical attention.
• The rash becomes infected.
• The rash doesn’t appear to be improving within 48 hours.

In the meantime, be gentle with your skin when you have a rash:

• Use mild cleansers and avoid scented bar soap.
• Wash with lukewarm water, not hot water, which can be drying.
• Pat the rash dry, don’t rub.
• Don’t cover the rash with gauze or clothing.
• Stop using makeup or lotion that may have triggered the rash.
• Try not to scratch the rash. Scratching could make it worse and could lead to infection.
• Apply an over-the-counter hydrocortisone cream to the rash if it’s itchy. Calamine lotion can also help relieve rashes from chickenpox, poison ivy or poison oak.

Rashes are some of the most annoying symptoms we deal with, but the right medical care will have you comfortable in your own skin in no time.

The dermatologists at Edward-Elmhurst Health have specialized training and state-of-the-art tools to help you with every kind of skin, hair and nail condition. Find a specialist.