The investigation was performed on 145 workers of Epoxy Resin Department of a chemical enterprise in Nizhny Novgorod Region of Russia. The examined persons had occupational skin contact both with epoxy resins (ED-16 and ED-20), and amine hardener (diethylentriaminemethylphenol). The air concentrations of volatile component of epoxy resin, epichlorohydrin, never exceed 1 mg/m3.

Dermatological examination revealed ACD in 35 workers (24%). Moreover, 68 persons (47%) without skin pathology at the moment of examination reported about itching eruption on hands or face in the past (during their work in Epoxy Resin Department). Those persons connected appearance of the rash with occupational allergens. No signs of ACD were found both during examination and in anamnesis only in 42 workers of the Department (29%).

So 103 workers of the Department formed the main group (35 workers with ACD and 68 workers with ACD signs in anamnesis). Group of comparison consisted of 42 workers who never suffered ACD in the past, despite of contact with occupational allergens. Thus, main group consisted of persons with presumed predisposition to ACD, and the group of comparison consisted of persons without such a predisposition.

We have compared the frequencies of several anamnestical indicators in these two groups of workers to define possible risk factors of ACD. Anamnestical data were collected using specially developed questionnaire with 126 questions.

Statistically significant differences (p<0.05) were found between main group and group of comparison for frequencies of the following indicators:

1. gender;

2. month of birth;

3. place of living (its distance from work);

4. occupational contact with hepatotoxical chemical substances in the past;

5. dermatomycoses and onychomycoses in anamnesis;

6. symptoms of respiratory allergy in anamnesis.

RISK FACTORS OF ALLERGIC CONTACT DERMATITIS

Frequencies of some indicators in workers with and without ACD

The clinical estimation of some obtained data might be rather sophisticated.

Perhaps the influence of mycotic infection on ACD can be explained the most easily, because investigators suppose that mycoses can play a significant role as an ACD risk factor [1].

It is well known that respiratory allergy often accompany skin allergy, so the interpretation of the higher incidence rate of respiratory allergy in the workers with ACD is quite clear.

Connection of handling hepatotoxical substances and incidence of ACD is also not difficult, because even the slight hepatic disorder can be a risk factor of allergic skin disease [4].

Living in the place situated rather close to the work place can mean additional contact with microdoses of occupational allergens at home, this obviously can increase incidence rate of allergic diseases, including ACD.

The higher incidence of contact sensitisation in female workers than in male has already been described by investigators [2]. Nevertheless, there is no clear explanation for this phenomenon: either it results from some peculiarities of female skin and immune system, or it can be connected with women's greater occupational exposure to contact allergens.

It is rather hard to explain satisfactory how month of birth can influence predisposition of a person to ACD. However such a relation (concerning non-occupational allergy) has been described [4,6]. One of hypothetical mechanism of such relation could be, perhaps, the higher incidence of viral infections in pregnant women during autumn and winter, that can result in some negative influence on immune system of foetus and, after many years, immune system of worker handling industrial allergens.

Thus, basing on performed investigations, we found that the following anamnestical and sociodemographical data could be risk factors of ACD for the workers contacting with industrial allergens at workplace:

· female gender;

· month of birth from March to May;

· living in less than 5 km from place of job;

· occupational contact with hepatotoxical chemical substances in the past;

· respiratory allergy in anamnesis;

· dermato- and onychomycoses in anamnesis

The obtained quantitative data concerning the influence of listed risk factors on ACD incidence were used to develop a computer program for evaluation of ACD risk for an individual person handling allergens at the workplace. Demo-version of such a program named "Predict" is available from Nizhny Novgorod Research Institute of Hygiene and Occupational Pathology.

1. Bannikov EA, Anton'ev AA, Makarova LE, Beker VP, Kiseleva LL The early detection of allergic dermatoses and mycoses of the feet in workers in contact with phenol-formaldehyde resins. Vestn Dermatol Venerol 1990;(3):19-21.

2. Kanerva L, Jolanki R, Toikkanen J Frequencies of occupational allergic diseases and gender differences in Finland. Int Arch Occup Environ Health 1994;66(2):111-6.

3. Karachaliou FH, Panagiotopoulou K, Manousakis M et al. Month of birth, atopic disease, and sensitization to common aeroallergens in Greece. Pediatr Allergy Immunol 1995 Nov;6(4):216-9.

4. Karuna BI Eczema. Kiev, 1989.

5. Manson MM Epoxides-is there a human health problem? Br J Ind Med 1980 Nov;37(4):317-36.

6. Nilsson L, Bjorksten B, Hattevig G et al. Season of birth as predictor of atopic manifestations. Arch Dis Child 1997 Apr;76(4):341-4.