urticaria is an immediate, type 1, antibody-mediated hypersensitivity. It
appears within minutes of contact and disappears within a few hours.
2Creosote is different from the other chemicals
listed in that it causes a photoirritant contact dermatitis. There are also several foods
that can cause this type of reaction, including lime, celery, parsnip and fig.
Other occupations with exposures to skin sensitizers: Morticians and embalmers
(formaldehyde, glutaraldehyde and rubber chemicals); Foundry workers (formaldehyde, isocyanates and
amines); Welders (colophony flux, chromium and nickel); Photo processors (Metol, thiourea,
CD-2,CD-3, CD-4, formaldehyde, phenidone, phenols and amines)