On rare occasions, exposure to methacrylates (MAs) may induce mucosal
symptoms. Three patients, two dental laboratory workers and one hearin
g aid laboratory worker, are presented. All three had allergic contact
dermatitis from MAs which disappeared after avoidance of contact with
uncured MA compounds. Two of the patients, the dental laboratory assi
stant and the hearing aid worker, had also developed symptoms of conju
nctivitis. Both were exposed to chemically curable and light-curable M
As. The association between their conjunctivitis and type IV allergy t
o MAs was supported by the following observations: 1) sensitization to
several MAs including methylMA, 2-hydroxyethylMA, ethyleneglycol diMA
, triethyleneglycoldiMA, tetrahydrofurfuryldiMA, and 1,4-butanedioldiM
A, as well as to pentaerythritol triacrylate; 2) simultaneous appearan
ce of their eye symptoms and allergic contact dermatitis; 3) high expo
sure to MAs because of disturbances of ventilation; 4) disappearance o
f the eye symptoms during holidays; and 5) opthalmologist's findings o
f follicular conjunctivitis with some papillae, eosinophilia, and lymp
hocytosis in conjunctival scrapings corresponding to allergic contact
conjunctivitis. In addition, the activation of eosinophils in the conj
unctival scrapings was demonstrated with the monoclonal antibody techn
ique, and an elevated level of eosinophilic cationic protein was found
in the tear fluid. Our cases suggest that conjunctivitis may be cause
d by type IV allergy to MAs, although type I allergy (even though pric
k tests were negative), other hypersensitivity mechanisms, or irritati
on cannot be excluded. 4H-Gloves(R) seem to give adequate hand protect
ion even to allergic patients. More attention should be paid to ventil
ation systems if MA exposure occurs, In some cases, patients with eye
symptoms need to be patch tested. (C) Munksgaard 1996.