Challenges in diagnosing shampoo allergy.

Shampoos for Patients with Irritation and Allergy

 

Of the 10-30 ingredients that are present in modern shampoos, it's possible to be irritated or allergic to one of the components.  Diagnosing a true shampoo allergy is not easy as patients don't necessarily present to clinic with a red scalp immediately after using a shampoo and say that they have a shampoo allergy. Rather patients with sensitivities to an ingredient in shampoos may present with dermatitis of the eyelid, neck, ears, face, back and sometimes the scalp. 

Patients with shampoo allergy are frequently not convinced it's their shampoo that is causing problems. They may change their shampoo brand only to find that at the dermatitis does not clear. Their (incorrect) conclusion is therefore that it can't possibly be a shampoo problem. However, there are so many similar ingredients in shampoos that sometimes a switch form one shampoo to another doesn't actually remove the allergen!

There are several potential allergens in shampoos. Of 179 shampoos analyzed in a study by Zirwas and colleagues, 170 had fragrance, making it the most common allergy. CAPB was second palace allergen (53 %),  MCI/CI was third place (51. 4 %),   formaledye releasers were fourth (48 %) and propylene glycol was fifth (38 %).  Vitamin E and parabens are sixth and seventh. 

About 1-4 % of the population has fragrance allergies and the incidence of fragrance allergy is increasing.  Given the large proportion of shampoos that have fragrance it can be quite difficult to find a shampoo that does not have fragrance. 

Not everyone needs to change their shampoos. The vast majority of people do not have problems with common shampoos. However, if there is any suspicion that an ingredient in a shampoos might be irritating or causing allergy, a switch to an low irritant - low allergen shampoo might be considered. Consultation with a dermatologist who specializes in contact allergy would also be appropriate in many situations. 

Interested individuals may wish to review our website for our handouts on shampoos that don't contain fragrance and shampoos that are devoid of ingredients like CAPB, MCI/MI, formaldehyde releasers and propylene glycol.