There are actually several types of heat-related rashes you can get, one of which causes bumps that sting, and another that doesn't hurt, but does cause fluid-filled bumps. Though intertrigo is categorized separate from heat rash, it is often caused or at least exacerbated by heat. To avoid heat-related skin conditions, try to keep your skin adequately clean and cool [source: Mayo Clinic].
Types of Skin Rash
So, you've got a red, raised, super itchy rash and you want to figure out what it is. Unless you've been walking barefoot through poison ivy, it's going to take a little research, and probably a physician, to solve the puzzle. But you might be able to narrow down the possibilities by considering a few things. Basically, most rashes fall into one of the following categories:
- Localized rashes caused by a bacterial or fungal infection
- Localized rashes that are caused by direct contact with an irritant or an allergen
- Localized or widespread rashes that are caused by an allergic reaction to some type of medication or a virus
To determine your rash type, consider what it looks like and what you've been exposed to such as any new medications, potential irritants or allergens. Then try comparing that information with descriptions of some common rashes, such as:
- Heat rash: Small bumps that are either fluid-filled or look like blisters can be a result of heat rash, especially if you've been out in the heat, been sweating, and/or wearing tight clothing.
- Intertrigo: If you have a bright red rash in moist areas where your skin rubs together (think under your arms, behind your knees, or in other skin folds), you may have intertrigo.
- Medicine rash: If a rash suddenly appears after you've just started on a new antibiotic, anti-seizure medication or diuretic, you might have a medicine-related rash. This rash starts out as small red splotches that quickly spread to cover large portions of your skin.
- Ringworm: Contrary to its name, there are no worms involved here. Instead, this rash is caused by a fungal infection. It looks like an expanding ring, which grows outward.
- Swimmer's itch: If you've been swimming in not-so-clean water, you may have swimmer's itch, which is a mild rash of itchy red bumps caused by parasites [sources: Mayo Clinic, Cleveland Clinic]
While these are fairly common, there are some rashes that are even more so. Keep reading to see what they are and how they are likely to manifest on your skin.