Occupational Asthma and Occupational Rhinitis in Hairdressers

Gianna Moscato, MD; Patrizia Pignatti, PhD; Mona-Rita Yacoub, MD; Canzio Romano, MD; Sandro Spezia; Luca Perfetti, MD


CHEST. 2005;128(5):3590-3598. 

In This Article

Materials and Methods

All hairdressers (n = 47) referred to our unit for suspected OA from 1996 to 2004 underwent clinical and occupational histories, skin-prick tests (SPTs) for common allergens and latex, patch test for sensitizing agents used in hairdressing saloons, total and specific IgE for common allergens and latex, spirometry, bronchodilator testing, methacholine challenge, and specific inhalation challenge (SIC). In 14 patients, SPTs for ammonium persulfate were also performed. A subgroup of 21 patients also underwent sputum induction and processing to assess airway inflammation before the SIC.

Forty-seven hairdressers (43 women; mean age, 25 years; range, 17 to 52 years) consecutively referred to our allergy unit from 1996 to 2004 for suspected OA were studied. A detailed occupational history was obtained from the patients, and the following information was obtained: description of the current and previous job; specific tasks; products used in the work place; modality of exposure (cutaneous, respiratory); type of symptoms (bronchial, nasal, cutaneous); duration of exposure before onset of symptoms; duration of symptoms from onset to diagnosis; relationship between symptoms and periods at and away from work (stop/resume test); relationship between symptoms and specific tasks and/or specific agents; date of the last symptoms; and date of last exposure. Information on personal and family history of atopy and smoking habits was also obtained. At the time of diagnosis (baseline), the patients did not have any respiratory infection symptoms and had not received oral steroids or antihistamines for at least 2 weeks, anticholinergic or adrenergic bronchodilator or sodium cromoglycate for at least 24 h, and slow-release theophylline or inhaled steroids for at least 48 h before the challenge.

Asthma was diagnosed according to international National Institutes of Health/World Health Organization guidelines.[20] OA was diagnosed by the following criteria:[21,22] clinical history suggesting work-related asthma, diagnosis of asthma, and positive response to SIC.[23]

SPTs for common inhalant allergens[24] and for latex were performed with commercial extracts (Lofarma Allergeni; Milan, Italy). To better evaluate the underlying mechanism of ammonium persulfate in inducing asthma, 14 of 21 patients with a positive response to the SIC with this compound (see below) were also submitted to SPTs with ammonium persulfate; 7 of 21 patients refused to undergo the test. The test was performed only in patients with a positive SIC response to ammonium persulfate due to ethical reasons (possible risk of sensitization by SPT to an agent the patient is occupationally exposed to). The test was carried out using freshly prepared ammonium persulfate solutions at a concentration of 1% and 5% weight/volume in saline solution.[16]

Histamine was used as a positive control, and saline solution was used as a negative control. Each test was read after 20 min. SPTs with ammonium persulfate were also read at 2 to 4 h and at 24 h. Apositive reaction was defined as a wheal diameter ≥ 3mm in the absence of a reaction to the control diluent and in the presence of a positive reaction to histamine.[25]

Atopy was defined by at least one positive SPT response to common allergens. Patch tests were performed by application of agents (FIRMA; Florence, Italy) on the back with readings at 48 h and 72 h.[26] Diagnosis of allergic occupational dermatitis was made in presence of dermatitis, positive patch result to a occupational agent, exposure to the agent, and positive stop/ resume test result. Total and specific IgE for common inhalant allergens and for latex were also measured (UniCAP System; Pharmacia AB; Uppsala, Sweden).

Spirometry was performed according to European Respiratory Society guidelines[27] by means of a computerized water-sealed spirometer (BIOMEDIN; Padova, Italy). Bronchial challenge with methacholine was performed by means of a nebulizer (MEFAR; Brescia, Italy) connected to a dosimeter as previously reported.[28] The provocative dose of methacholine causing a 20% fall in FEV1 (PD20) was expressed in micrograms and was considered to be positive if the PD20 was < 1,000 µg. The reversibility test was performed with the nebulization of salbutamol (100 µg followed after 5 min by another 100 µg) and the result was considered positive if there was an increase in FEV1 > 12% (in addition to an absolute increase of 200 mL).[29]

Each patient signed an informed consent approved by the ethical committee of our institute for the SIC. SICs were performed as described by Pepys and Hutchcroft[23] and Vandenplas and Malo.[30] Each patient underwent the challenge with any suspected sensitizing agent and/or product present at the workplace. SICs with single agents/products were performed following the criterion of increasing likelihood of a positive response (eg, the more suspect the agent from the history, the later the SIC). Tested agents were ammonium persulfate (n = 44), paraphenylenediamine (n = 36), latex (n = 24), hair-waving solutions (n = 6), and permanent hair dyes (n = 4).

The challenges were performed in an inhalation chamber (7.46 m3) as follows: as a control, and on the first day the patient was exposed to ethanol for 30 min (cumulative exposure). If no significant change (variation of FEV1 ≥ 10%) in FEV1 occurred within the following days, the patient was exposed to the suspected agents/products.

SIC with ammonium persulfate was performed by a 30-min nebulization of a solution of 8 mg of ammonium persulfate in 3 mL of distilled water. The concentration of ammonium persulfate in the inhalation chamber was evaluated, during two different challenges on separate days, by air sampling at 10', 20', and 30'. after starting exposure using an air pump with a constant flow of 3 L/min. The analysis was performed by means of mobile- phase ion chromatography. A mean concentration of 1.01 + 0.11 mg/μL over the 30-min exposure was measured.

SIC with paraphenylenediamine was performed by a 30-min nebulization of a solution of 12.5 mg of paraphenylenediamine in 3mLof ethanol 65% in water. SIC with latex was performed as previously described.[31] SIC with hair-waving solutions (n = 6) and hair permanent dyes (n = 4) were performed with the occupational method.[7] Each patient was consecutively exposed for 2, 4, 8, and 16 min, resulting in a total exposure time of 30 min.

Spirometry and peak expiratory flow were measured after each exposure. Spirometry and peak expiratory flow were monitored also at 5, 15, 30, and 60 min after the end of exposure and then every hour for 7 h and after 24 h. The test result was considered positive in case of FEV1 fall ≥ 20% compared to baseline. The responses were classified into three patterns: early if they occurred within 1 h after the end of exposure, late if they occurred after > 1 h, or dual, characterized by both an early and a late response.[30]

A diagnosis of occupational rhinitis was made in case of a positive nasal response. In the absence of international guidelines for the diagnosis of occupational rhinitis, the diagnosis was made in the presence of a positive symptom score after the SIC as described below. In order to evaluate nasal response to suspected occupational agents, symptoms were assessed and rhinoscopy was performed at 5, 15, 30, and 60 min after the end of exposure (on the control day and during SIC) and then every hour for 7 h and at 24 h. At each time point, the following symptoms and signs were assessed and recorded: nasal itching, sneezing, nasal obstruction, rhinorrhea, and mucosal edema. Each parameter was scored from 0 to 3. If the total score at each time point was ≥ 6, without any change on the control day, a positive nasal response was recorded and occupational rhinitis to that agent was diagnosed.

Sputum was induced and processed as previously described[32] according to international guidelines[33] in 10 patients with positive SIC findings to ammonium persulfate and in 11 SIC-negative patients. The test was performed before the specific challenge, and in only the patients observed after 1999, when it was introduced into the practice of our laboratory.

Briefly, FEV1 was measured before and 10 min after inhalation of salbutamol (200 µg). Ultrasonically nebulized (De Vilbiss 65; De Vilbiss; Somerset, PA) hypertonic (4.5%) saline solution was inhaled for 1, 2, 4, 6, and 16 min. FEV1 was measured 1 min after each inhalation period. Patients were instructed to rinse their mouth with water and to cough and produce sputum after each inhalation period.

Induced sputum was conserved at 4°C before starting the processing within 2 h. Sputum plugs were selected from saliva, weighed, and treated for 15 min with a volume (in microliters) of 0.1% dithiothreitol (Sputolysin 10%; Calbiochem; La Jolla, CA) diluted in 3% bovine serum albumin (BSA), equal to four times (in microliters) the weight (in milligrams) of sputum plugs. Then, an equal volume of BSA (phosphate-buffered solution) was added to the mixture and filtered with a 70 μmol/L cell strainer (Falcon; Becton Dickinson; Franklin Lakes, NJ). Cells were separated from supernatant by centrifugation at 300g for 5 min and diluted in a volume of 1% BSA in phosphate-buffered saline solution equal to the volume of dithiothreitol added at first. Cell count and viability by Trypan blue exclusion were determined with optical microscopy. Cytospins were stained (Diff-Quick; Dade Diagnostika GmbH; Unterscheiheim, Germany) and analyzed for differential cell count. Sputum samples with < 30% of squamous cells were considered acceptable. Significant eosinophilic airway inflammation was defined when sputum eosinophils were > 3%.[34]

Age was expressed as mean (range); other variables were expressed as median (first to third quartiles). When range was used, it was indicated. Data were analyzed by means of Mann- Whitney U test, X 2 test, and Spearman rank test; p values < 0.05 were considered significant. Analysis was performed using statistical software (Statistica for Windows, release 4.5; StatSoft; Tulsa, OK).


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