A skin allergy can result from anything inhaled, ingested, injected or applied to the skin. Exposure to an allergen can cause skin allergic dermatitis, but some allergens may also lead to a more severe systemic allergic reaction, depending on your immune system's response.
Typical Skin Allergens
An allergen is anything your body recognizes as foreign. Your body mounts an immune response to fight off this perceived foreigner. The hallmark of the skin allergic reaction is itchy rash. Visible signs can range from
- A sometimes-red, fine, bumpy rash
- Bumps and blisters that ooze
- Swelling at the area of contact
- Hives (a more widely spread skin rash)
In a severe allergic reaction beyond the skin, you can have difficulty breathing or go into anaphylactic shock and unconsciousness.
It is difficult to avoid exposure to allergens because some of the common skin allergies are caused by substances that are used widely in household goods, fashion, cosmetics, and personal care products. Some of the more common skin allergens are:
1. Metals (Nickel and Gold)
Nickel metal is a common skin allergen. Gold jewelry can also cause an allergic skin reaction, especially because it is sometimes mixed with nickel. Items nickel is present in include:
- Eyeglass frames
- Belt buckles
- Studs on clothes, shoes, belts, neck collars
- Clothing clasps, snaps and hooks watches
- Kitchen utensils
- Body piercings
It is not uncommon to develop an earlobe allergy to the needle or the earring inserted after the ear piercing, or an allergic reaction elsewhere after any other body piercing. Titanium should be used for all piercings if you have any allergies to metals.
To avoid these allergens elsewhere, look for items made of plastic or coated metals.
Fragrances are a common cause of skin allergies because they are added to numerous items. These items include:
Unscented does not mean fragrance free; they often use another chemical related to Balsam of Peru (another common allergen) to block the scent. Look for fragrance-free products to avoid these allergens.
Thimerosol is a mercury compound used as a preservative in vaccines. It is also a preservative used in products like:
- Contact lens solutions
- Eye creams
- Makeup remover
Avoid products with Thimerosol if you have an allergic reaction any of these items.
Formaldehyde is a resin used in fabrics to make them waterproof, or wrinkle and shrinkage resistant. It can also be found in:
- Solvents, adhesives, paints
- Paper products
- Medications (as a preservative)
- Household cleaners and disinfectants
- Medical labs (as a tissue fixative)
- Funeral parlors (embalming fluid)
- Fiberboard and plywood
Reactions can range from a skin rash to burning eyes, throat and nose symptoms, or shortness of breath.
Use formaldehyde-free products if you develop and allergy to the above products. This includes avoiding wrinkle-free clothes. However, washing your clothes repeatedly in hot water can often reduce the formaldehyde exposure from the fabric finishes on your clothes.
5. Balsam of Peru
Balsam of Peru is the resin from the balsam tree found in South America. It is found in multiple everyday products, including:
- Food and food flavorings
An allergic skin reaction to Balsam of Peru is usually an itchy red rash.
Avoid food flavorings, processed foods, and any product with Balsam of Peru as an ingredient.
Neomycin is a topical antibiotic cream, ointment or liquid drops. It is sometimes combined with other antibiotics such as Bacitracin, or with topical anesthetics for pain relief. Neomycin can be found in in the following products:
- Topical first aid for skin
- Eye and ear drops
- Pet/veterinary care products
It can cause a typical red rash with fine bumps at the contact area. In the eye it can cause itching, redness and tearing. In the ear there can be itching, pain and fluid drainage. Rarely topical Neomycin can cause a more systemic reaction.
To avoid exposure to this allergen, read ingredients and product labels carefully and consider wearing gloves when handling pet foods.
Inform your doctor of this allergy before he prescribes eye or ear drops or other preparations containing this ingredient.
7. Paraphenylenediamine (PPD)
PPD is present in several dyes and ink products. Examples include:
- Permanent, demi-permanent and semi-permanent hair dyes. Darker hair colors have increasingly more PPD added than lighter colors.
- Black henna skin tattoo ink
- Printer and photocopy inks
- Photographic developer
- Fabric and fabric dyes
- Products made of black rubber
Important information about PPD in all of these products include:
- The allergic contact dermatitis can be a mild, red itchy rash at the site.
- A more severe reaction can occur with swelling and oozing bumps at the contact area.
- With hair dyes, the severe reaction can lead to swelling and oozing of the scalp and swelling of the face, eyes, and neck. It can also lead to hair loss.
- Hair dye allergy can also result in a full-blown systemic allergic reaction, including difficulty breathing and, occasionally, anaphylaxis.
To avoid exposure, use PPD-free hair coloring products or avoid darker hair dyes. Elumen Hair Color (Goldwell Cosmetics, Linthicum Heights, MD) is a PPD-free hair color that comes in multiple shades and last 4-6 weeks.
If you are allergic to PPD, you should also avoid black henna tattoos as well as contact with printer and photocopy inks and black rubber products. It is also advisable to avoid textiles dyed with PPD-containing dyes, especially darker colors.
Latex products are made from the milky liquid from rubber trees. Proteins in latex cause the allergic reaction. Latex is used in
A rash occurs at the point of contact. Some people, however, can get itchy eyes and have difficulty breathing and anaphylaxis.
Use latex-free gloves and condoms and avoid other items on this list that are made with latex.
9. Cobalt Chloride
Cobalt chloride is a metal used as a coating or an ingredient in
- Snaps, buttons, buckles
- Hair dyes
- Medical products
- Dental crowns
Symptoms include a rash, itching, redness, swelling and blisters on the skin.
Look for cobalt chloride-free products and wear plastic or fabric-covered clothes and belt fasteners.
Quaternium-15 can cause an itchy, allergic red rash at the area of contact. It is a preservative used in:
- Shampoos and hair conditioners
- Nail polish
- Mascara, eyeliners, eye shadow
- Sunscreens and self-tanning lotions
- Ink, adhesives, paint, particle boards
- Floor waxes and polishes
Critically read the labels of these products to avoid contact.
Poison ivy, poison oak and poison sumac contain the same allergen, urushiol. Reaction is usually an allergic dermatitis or oozing blisters at the point of contact. Some people may get a more generalized rash and fever.
Avoid walking in the woods or coming in contact with pets who were in the woods if you are allergic to these plants.
Photoallergic Contact Dermatitis
Additionally, in some people, certain products can cause an allergic reaction known as photoallergic contact dermatitis, because it occurs only when they are in the sun. These products include:
- Sunscreens with substances such as para-aminobenzoic acid (PABA), benzophenones, salicylates and oxybenzones
- Medications such as antibiotics and ibuprofen
- Oil from the skin of a lime
The red rash often resembles a sunburn on sun-exposed areas.
Look for sunscreen products without the above ingredients and, if possible, avoid oral medications which cause you to have a rash when in the sun. If you need to take these medicines, stay out of the sun while you are using them.
Skin Allergy Testing
Some allergens cause a reaction on first contact, others require repeated contact. If you believe you have an allergy to a product read the label to see if it contains any substances on this list. If you have a severe reaction, repeated reactions, or multiple allergies see your primary care doctor, a dermatologist or an allergy specialist for allergy testing.