Allergy to metals, rubber gloves, fabrics, cosmetics, deodorants, etc. (Contact Allergy)
Sometimes contact with different materials (usually but not always extended contact) may cause inflammatory skin reactions. In a general sense, inflammatory skin reactions are called dermatitis. Some of these dermatitides are allergies, meaning that they are mediated by the immune system as an attempt of rejection of a material that the body identifies as harmful.
About 20% of work-related health problems are skin problems. Of these, a significant percentage (79-90%) is contact dermatitis. In practical terms, four types of contact dermatitis can be distinguished:
- Irritative dermatitis: Which accounts for 80% of all cases of contact dermatitis. This reaction is similar to a skin burn (ranging from just skin redness to full blown grade 3-burn like skin ulcerations). These reactions will occur in any person if his skin is exposed to an inappropriate concentration of a harmful substance for long enough time. An example of these reactions are acids which will lead to skin damage and skin reactions in every person. These reactions usually occur immediately, in a few minutes. The solution is avoiding contact with these substances, use of protective devices (in example substance-resistant gloves).
- Photocontact dermatitis: occurs in areas exposed to sunlight (or alternatively to UV light) and is manifested in a similar way to skin burns after excessive sun exposure. This reaction occurs after exposure to substances which sensitize the skin to UV light (which is part of the natural radiation of the sun). These sensitizers can belong to 2 groups:
- 1. Photoallergic substances: in example after cutaneous exposure to PABA, a substance that exists in several lotions for protection against solar radiation. For these substances to be able to sensitize the skin, a previous exposure is needed.
- 2. Phototoxic substances: in example a skin reaction after sun exposure in people who are being treated with certain antibiotics from the tetracycline family. For phototoxic substances to produce a skin reaction, previous exposure is not required.
- Contact Urticaria: is characterized by an itchy rash that appears rapidly after contact with the allergenic material (sometimes fish, perfumes and other diverse materials). The skin reaction is transient and disappears a few hours after cessation of exposure to the culprit.
- Allergic contact dermatitis or Hypersensitivity: is characterized by a relatively slow response in the skin in contact with the allergenic material. Possible allergenic materials are, among others, metals (especially nickel), and the reactions are manifested by swelling, redness in the area of contact, for example in the ears after contact with earrings.
Diagnosis of the exact cause is based on the information that the patient provides, the timing of the reaction, the type of reaction, the time needed to elicit the reaction, the time of cessation of the reaction, material exposure and distribution and the reaction. If allergic contact dermatitis is suspected, the allergist may perform a patch test. Patch test is based on skin exposure to a suspected material for 48 hours. Presence or absence of a skin reaction underlying the zone of exposure to the suspected material will confirm or rule out a connection between the investigated material and the skin reaction. Sometimes it is necessary to see the patient again even up to 48 hours after removing the patch because of borderline reactions that may increase with time.
Contact dermatitis treatment is based on avoiding exposure to the culprit material or alternatively using protective measures such as gloves. Contact dermatitis is a common occupational problem (in example use of gloves and allergy to rubber/latex, the raw material of ordinary gloves), a cosmetic problem (allergy to cosmetics, to hair dye, to henna-the common tattoo dye).
It is important to note that people with metal allergies should provide this information to any treating physician if a foreign body implantation is planned, such as a tooth implant or an artificial joint replacement, among others. Other contact allergies should also be reported to the treating physician as they may have consequences for further treatments (in example allergy to thimerosal, a common stabilizing material in the pharmacologic industry and in vaccines).
Treatment to this type of allergic reactions includes steroids (ointment or oral) and antihistamine drugs.