National Hairdressers Day

Hairdressers are particularly prone to hand dermatitis, and today seems like a great day to discuss why. The constant wet and dry of their hands drys the skin and weakens its protective barrier. With the addition of the large number of irritating chemicals and the possibility of developing allergies to other chemicals, hairdressers have pretty beaten up hands.

PPD (paraphenylendiamine) in black hair dye and glycerol monothioglycolate in hair perming solutions are two allergens that hair dressers come ac. People are exposed to them and over time can become sensitized. This means that the immune system recognizes the chemical as an allergen and mounts an immune response to it upon subsequent exposures.

PPD is also used in "black henna". Henna is naturally green and has not been reported as an allergen before. However, PPD is used to blacken the color, so someone can become sensitized to PPD without having used hair dye. This web page has a great picture of allergic contact dermatitis to black henna (PPD).

Vinyl gloves are effective at preventing PPD sensitization, but not glycerol monothioglycolate sensitization. How do you treat allergic contact dermatitis? Avoidance is the only way to prevent it. And topical steroids can be used to help current lesions heal.

Take home points:
1. Black hair dye, black henna tattoos, and perming solutions contain common allergens
2. People can become allergic to something with repeated exposure over time


Redlick F, DeKoven J. Allergic contact dermatitis to paraphenylendiamine in hair dye after sensitization from black henna tattoos: a report of 6 cases. CMAJ. 2007 Feb 13;176(4):445-6.

Fisher AA. Management of hairdressers sensitized to hair dyes or permanent wave solutions. Cutis. 1989 Apr;43(4):316-8.

I'm using Neosporin, but my wound keeps getting worse!

I saw two patients today with the same complaint and the same problem. Neosporin is an antibiotic ointment containing neomycin, an aminoglycoside antibiotic. Neomycin can be used topically or orally, but it is most commonly used as a topical medication. Neosporin is mainly used as an agent to help with wound healing. So why did these two patients have what appeared to be normal wounds that were actually getting worse when they used Neosporin?

Neomycin is one of the top 10 topical allergens in the US. The allergic reaction usually presents as a red, raw area similar to eczema. It will look like the wound is spreading or getting worse instead of healing. Just stop using the Neosporin and be sure to avoid all ointments (like triple antibiotic ointment) that contain Neomycin as well. Also, people who are allergic to Neomycin show a high incidence of allergic reactions to Bacitracin, another topical antibiotic (usually sold as Polysporin). Finally, it's important to remember that you had this allergic reaction to Neosporin because you may be allergic to oral medications that are in the same class of drugs. But when you take the oral aminoglycosides, you could have an eczematous reaction over your whole body or even have anaphylactic shock. Look back at my previous post about Vaseline being used for wound healing. It's a great alternative for people who are allergic to Neomycin or Bacitracin.



Hopefully my paper will be accepted and I'll use it as the reference here :)