Getting a rash from sunscreen can be nearly as unpleasant and uncomfortable as getting a sunburn, and should be avoided if possible. A rash from sunscreen is usually caused by an allergic or irritant reaction to one or more of the ingredients in the lotion, and can lead to itching, burning, or reddened skin and hives. In order to avoid getting a rash from sunscreen, look for brands that do not contain irritants, track down the source of the rash with medical assistance, and make sure the rash is truly coming from the sunscreen and not another factor.
Several of the most common ingredients in sunscreen can cause rashes and skin irritation. Some of the active ingredients, such as para-aminobenzoic acid (PABA) are known to cause allergies in some people. Ingredients that end in "benzophenome" or "salicylate" may also be active sunscreen components that may be causing a rash. Choosing sunscreen made of zinc oxide is usually the best option for people allergic to active sunscreen ingredients; although zinc oxide does not blend into the skin as well as other types of sunblock, it is rarely linked to allergies and provides adequate sun protection.
In addition to the active ingredients that make a sunblock work, several inactive additional ingredients can also cause a rash from sunscreen. Fragrances, preservatives, nut oils, and artificial ingredients such as parabens can all be responsible for an allergic reaction. Nut, fruit, flower, and spice ingredients are all commonly used in sunblock, and should be avoided by anyone with existing allergies or sensitivities to a specific substance. Some sunblock companies offer a fragrance free or natural ingredient formula that may be suitable for those with certain allergies.
In order to track down exactly what is causing a rash from sunscreen, it may be necessary to visit a doctor for allergy testing. Allergy testing for skin reactions is often done through a patch test, in which small patches of the skin are treated with potential irritants and monitored for a reaction. In some cases, a blood sample may also be taken and used to test for specific allergic reactions. If switching brands or formulas still results in a rash from sunscreen, allergy testing may be a good idea.
Finally, it is important to determine if a rash is truly caused by sunscreen, or may be occurring due to another issue. Some people have an inherent sun sensitivity, which can cause rashes when the skin is exposed to sunlight. Others may be developing rashes due to a different cosmetic product, such as a new soap, shaving cream, or moisturizing lotion. Determining if sunscreen is a causing a rash is a process of trial and error; a person may want to try sitting in the sun for a brief period without sunblock to determine if a rash occurs, or showering with no additional products, then applying sunscreen and seeing if the rash suddenly appears. Allergy testing can also be a good way to figure out which products may be culprits behind a rash.