Occupational allergy after exposure to caddis flies at a hydroelectric power plant.

A cross sectional survey was conducted in a hydroelectric power plant in which the workforce was exposed to large numbers of caddis flies. 28 of 57 employees participated. About 50% of the participants reported work related eye, nose, and sinus symptoms and wheezing. Working in locations with greater exposure to caddis flies was significantly associated with work related symptoms. 17 workers (61%) were skin prick positive to a laboratory prepared caddis fly antigen (LCFA) made from the remains of caddis flies present in the plant and 11 (39%) had positive reactions to a commercial caddis fly antigen (CCFA). Workers stationed in heavily exposed areas were 3.7 times as likely to have a positive response to the LCFA (p = 0.009) and 5.3 times as likely to have a positive response to the CCFA (p = 0.036). 13 (46%) of survey respondents reported three or more work related symptoms. 10 (91%) CCFA positive workers reported three or more work related symptoms. Pulmonary function studies revealed slight, but not significantly decreased forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and FEV1/FVC ratios in workers who were skin test positive to either caddis fly preparation when compared with those who were negative. One worker who was skin test positive to both antigens had a cross shift fall in FEV1 of 20% predicted. Occupational allergy to caddis flies proved to be a significant health problem at this work site.

The frequency of skin test reactions to side-chain penicillin determinants.

BACKGROUND: Skin testing for immediate hypersensitivity to penicillins is usually carried out with reagents prepared from benzylpenicillin, and it is believed that side-chain-specific reactions to semisynthetic derivatives are rare. Because some experimental and clinical data suggest that antibodies can be induced to immunogenic epitopes on the side chains of penicillins, we looked for side-chain-specific reactions to skin testing in patients with a history of allergy to penicillins or semisynthetic penicillins. METHODS: One hundred twelve patients with a clinical history of allergic reactions to penicillins and other semisynthetic penicillins were skin tested an average of 4.9 +/- 0.7 years after their reactions with the major and minor determinants of benzylpenicillin and minor determinant mixtures of ampicillin, amoxicillin, or cloxacillin. RESULTS: In these patients the most common clinical reactions were urticaria and angioedema (36.6%) and exanthema (48.8%). It was found that 21 cases (18.8%) still exhibited immediate hypersensitivity reactions on skin testing. But of these 21 patients, skin test reactivity was limited in 47.6% to the semisynthetic penicillin reagents derived from ampicillin, amoxicillin, or cloxacillin; that is, skin tests were negative with the benzylpenicillin derivatives. Ampicillin and amoxicillin were the semisynthetic beta-lactams causing most clinical reactions (24.1% and 33.9%, respectively), and ampicillin was the most common penicillin derivative to which skin test reactivity occurred (38.1%), other than the benzylpenicillin derivatives (52.3%). CONCLUSIONS: IgE antibodies appear therefore to discriminate between benzylpenicillin and ampicillin or other semisynthetic penicillins in a significant proportion of patients allergic to penicillin. Although it has not been proved that side-chain-specific skin reactivity implies the presence of clinically significant immediate hypersensitivity to semisynthetic penicillins, it is possible that side-chain-specific reagents may be required to exclude possible immediate hypersensitivity to the penicillins in patients who reacted to these antibiotics clinically.