Having a skin rash can feel like you’re in a bizarre, dermatological version of Invasion of the Body Snatchers. Your skin is unhappy for some reason, and instead of doing the polite thing—chilling out—it’s going to express its displeasure. Boldly. Meet your new rash.
1. Is your rash itchy?
Itching is a really common side effect of all sorts of rashes, so it’s unlikely that you’ll figure out what’s going on from this symptom alone, Dr. Zeichner says. But some rashes aren’t usually itchy, so this is still a good question to ask yourself.
2. Does it have a clear edge?
If your rash has a clear edge, cut-off point, or pattern, the cause is pretty likely something external that is affecting your skin, Misha A. Rosenbach, M.D., associate professor of dermatology at the University of Pennsylvania’s Perelman School of Medicine, tells SELF. That’s as opposed to something internal, like an underlying medical condition, which would be less likely to create a clearly-defined rash.
3. Does your rash burn?
This can help narrow things down quite a bit. “There aren’t that many rashes that give a burning sensation,” Dr. Zeichner says. You’ll usually get a burning feeling if there is a break in your skin, Dr. Robinson says.
If your skin is red, inflamed, and burning, first check that you don’t have some sort of cut or actual burn. If it really seems like you have a burning rash, Dr. Zeichner says you could be dealing with something like shingles.
4. Is it blistering?
As you may know after trying to break in a pair of shoes, blisters often happen because something is rubbing your skin or otherwise putting too much pressure on your delicate epidermis, according to the U.S. National Library of Medicine. Unfortunately, they also happen because of skin conditions. In fact, blisters can often bead up due to dermatological issues, because a long list of conditions may cause this symptom.
5. Is your rash scaly?
In a perfect world, your skin cells will naturally bow out when their job is done, shedding in order to allow new, healthy cells to rise to the surface. (Fun fact, per the AAD: The human body typically sheds 30,000 to 40,000 old skin cells every day.) But sometimes this process doesn’t go as smoothly as it should.
6. Have you had this rash before?
The answer to this question can help you and your doctor figure out what’s triggering the rash. In some cases, chronic skin conditions like eczema or psoriasis are to blame, Dr. Zeichner says. But repeated rashes can also be a sign that continued exposure to something external is setting off your skin.
7. Have you tried a new cosmetic recently?
Contact dermatitis often crops up in response to products like soap, lotion, and makeup, Dr. Robinson says. Ask yourself if you’ve added anything new to your routine, but also keep this tricky fact in mind: You can develop this reaction to certain products even if you’ve been using them for ages. Sometimes it takes many exposures for your body to begin showing signs of irritant or allergic contact dermatitis.
8. Could it be related to the heat?
In a mild case of heat rash, you may just experience a swath of superficial, clear blisters on the top of your skin, the Mayo Clinic says. More involved cases can cause prickly, itchy red bumps, pus-filled sacs, and hard, skin-toned lesions that look a lot like goosebumps. Luckily, heat rash usually goes away after a few days of keeping your skin cool and stay out of the heat, but you should call your doctor if it lasts longer than that or seems to be getting worse, the Mayo Clinic says.
9. Do you have a fever?
If you have a fever along with your rash, it’s a good idea to get checked out by a medical professional, Dr. Rosenbach says. You could be having a serious allergic reaction to something like a medication, according to the Mayo Clinic. This combination of symptoms could also indicate an infection like shingles, mononucleosis, or even measles, according to the AAD.