Some shampoos contain ingredients that can cause allergic reactions in some people. To know how this works and possibly prevent it from happening to you or a loved one, you need to understand which ingredients in shampoos can cause such reactions and what can be done about it.
The most common symptoms of a shampoo allergy are itching and swelling of the skin on the scalp. This occurs as part of the inflammation response of the immune system. Usually, these symptoms go away when the shampoo is thoroughly rinsed out of the hair and off the scalp, although it may take a few minutes. Itching can be problematic because it's uncomfortable, and because continuous scratching can result in lesions on the scalp that further can be aggravated by the allergy and can result in infection. Other symptoms include pimples, a rash and dry scalp or dandruff.
Shampoos have many ingredients that can be the cause of a shampoo allergy. Among the most common are sodium lauryl sulfate and sodium laureth sulfate. Others include ammonium laureth sulfate, preservatives such as Kathon CG, and natural ingredients including chamomile, lavender, rose oil and fragrances.
Immediate treatment for a shampoo allergy generally is limited to a thorough washing of the scalp, neck and face, because removal of the allergen can reduce or eliminate the allergy symptom. If this doesn't help enough, cortisone ointments can be applied for relief of redness and itching. Switching shampoos is another simple but effective way to deal with the allergy, because the new shampoo will remove residue from the old shampoo that can still be causing irritation.
Although quite a few people are allergic to one or more of the ingredients in various shampoos, some of the symptoms of a shampoo allergy are mirrored by other problems. These problems must be ruled out before the shampoo allergy can be diagnosed properly. For instance, washing hair too often changes the pH of the skin, affects the number of bacteria and yeast on the scalp, and can rob the scalp of oil needed to stay healthy. The result can be dry skin that flakes, itches and is red and irritated, just as in a shampoo allergy.
Where to Get Other Products
If you suspect you have a shampoo allergy, you may be able to find a different shampoo that doesn't bother you on the store shelf right next to the old one that caused problems. However, most commercial stores have products that include many of the same ingredients and that are processed in the same way. As an alternative, you can try getting your shampoo from a natural or organic store. These shops have shampoos that are made without many of the usual additives and can be free of dyes and perfumes. If all else fails, ask your doctor for a product to relieve your symptoms, or for direction about what shampoo would provide minimal reaction.