Some of the most common causes of an allergic reaction on the neck are cosmetics, clothing detergents, and hair products. Cosmetics are often placed on both the face and neck, and many products contain substances that irritate sensitive skin. Clothing detergents that are not specifically formulated for sensitive skin and allergies can also cause an allergic reaction on the neck. In addition, people who have medium-length to long hair should be wary of what hair products they use, because the product will likely come into contact with their neck. Minor reactions usually do not require a doctor’s visit.
An allergic reaction on the neck is commonly caused by cosmetics like foundation and lotions. Cosmetics can have nut oils, essential oils, or dozens of other substances known to cause irritation in some people. The reaction might be hives, itching, or swelling. A widespread breakout can be avoided by testing a new product on a small portion of the skin first. In general, a person must be exposed to an allergen at least once before he or she has a reaction to it, so it may be wise to test the product a few times before applying it all over the face and neck.
Sometimes an allergic reaction on the neck is caused by a detergent. A person may experience hives, itching, and swelling, though the reactions are usually not severe enough to warrant seeing a doctor. Scented detergents in particular can lead to an allergic reaction when the clothing is worn. It is possible for the neck to be the only body part effected because of how often it rubs against the collar. Switching to an unscented detergent for sensitive skin may eliminate the problem.
Shampoos, hair conditioners, and other hair products also have the potential to cause an allergic reaction on the skin. When the shampooed or conditioned hair comes into contact with the neck, the allergen does too. As the day progresses, the itchiness and redness might get worse until the hair product is washed out. Some hair products have also been observed to contribute to acne breakouts. Basically, it is best to keep hair off the face and neck, especially when experimenting with a new product.
Taking an over-the-counter antihistamine and waiting the reaction out is a common course of action. If the hives, swelling, or itching seem severe, it may be necessary to seek medical attention. Most people are fine a few hours after the allergen is washed off.