Types of Facial Eczema: Allergic Contact Eczema

The face is a common site for allergic contact dermatitis. In allergic contact dermatitis the
immune system reacts to a specific chemical in the environment, producing a specific
allergic reaction. This usually occurs in people who have been exposed to the chemical
substance before and become ‘sensitised’ to it. Unlike irritant contact dermatitis, a
reaction may then occur following subsequent exposure to small amounts of the chemical,
causing allergic contact dermatitis.

Allergic contact dermatitis of the face can be caused by obvious direct contact with a
sensitising chemical such as a cosmetic, by contact with airborne substances such as
perfumed sprays and plant products, or by transfer of a sensitising chemical to the face by
the hands (e.g. nail varnish). Certain sensitising chemicals may affect characteristic areas
of the face, but the eczema may often be indistinguishable in appearance from atopic
eczema. Cosmetics are the usual culprits in allergic contact dermatitis affecting the face.
They contain fragrances, wool alcohols (lanolins), preservatives and dyes that can all
cause sensitisation. Allergy to ingredients of hair dyes may also cause severe allergic
contact dermatitis of the face. Nickel allergy is very common, affecting about 5% of
women. It usually causes earlobe dermatitis in allergic people who have been sensitised
(by ear piercing) and who then wear non-gold or silver jewellery. Less commonly, nickel
allergy may cause reactions to metal spectacle frames.

If allergic contact dermatitis is suspected patch tests may need to be carried out by the
dermatologist. Small quantities of potentially sensitising chemicals that are thought to be
relevant are applied to patches of normal skin on the back and held in place by adhesive
tape. This is removed after two days to look for an allergic reaction. The back is usually
examined again after a further two days to detect any delayed reaction. More details on
patch testing are available in a National Eczema Society fact sheet ‘Patch Testing’. If a
relevant sensitising chemical is identified, this should be rigorously avoided. In the case of
allergy to sensitising chemicals found in cosmetics, it is often necessary to obtain a list of
safe cosmetics from manufacturers. Your Pharmacist should also be able to help you
check the ingredients of a particular product. If in doubt, apply a small quantity of your
chosen cosmetic repeatedly to a small area on your forearm - significant allergy should
cause a localised itching rash.