The patch test reaction pattern in
nickel-positive and -negative female patients was compared.
Cobalt allergy was found in 24.8% of the positive patients. However, the occurrence of
allergy to other common agents, i.e.,
neomycin,
perfume mix,
balsam of Peru and
bacitracin, did not differ significantly between the 2 groups. Even in patients allergic to
nickel and
cobalt simultaneously, the frequencies were comparable.
Chromate and
PPDA allergy was significantly commoner in
nickel sensitive patients (p less than 0.05 and p less than 0.01). Erythematous or follicular reactions were seen most often to wood
tars,
propylene glycol,
formaldehyde,
cobalt,
chromate and
perfume mix. Reactions to
propylene glycol and
perfume mix were as frequent in both groups, whereas
formaldehyde,
cobalt and
chromate caused reactions more often in
nickel-positive patients (p less than 0.05) and wood
tars in negatives (p less than 0.05). Follicular reactions developed especially in patients who were positive to
nickel and
cobalt. The total number of non-specific reactions was not overpresented in
nickel sensitive patients, despite their multiple patch test reactivity.