How could I suddenly have dermatitis?
In allergic contact dermatitis, the allergen may be something that you have used for years without any problems. Even mild chemicals such as hexachlorophene in soap and acetone in nail polish remover can produce contact dermatitis if used repeatedly and over longer periods of time.
This may also be the case with certain topical ointments containing coal tar or steroids which you may have used over longer periods of time. Other hard to define causes include ingredients in medicinal lotions such as antihistamines, antibiotics, or antiseptics, plants, rubber, metals (such as nickel), dyes, cosmetics, and chemicals used in manufacturing such as those used to make shoe (glues) or clothing. Some substances cause dermatitis only when they contact your skin in the sunlight. Typical examples include shaving lotions, sunscreens, ointments containing sulfa drugs, perfumes and coal tar products. Other causes of contact dermatitis may be airborne, such as pollen, agricultural sprays etc.