Quantitative skin prick and bronchial provocation tests with platinum salt

Area of Science:

• Occupational Medicine
• Allergology
• Pulmonology

Background:

• Occupational asthma due to platinum salts is a frequent condition in platinum refinery workers.
• Diagnosis typically relies on work-related symptoms and positive skin prick tests (SPTs) for platinum salts.
• Bronchial provocation tests (BPTs) are not routinely used due to perceived high specificity and sensitivity of SPTs.

Purpose of the Study:

• To assess the utility of SPTs and BPTs with methacholine and platinum salts in platinum refinery workers.
• To evaluate the correlation between SPTs, BPTs, and methacholine responsiveness.
• To determine the safety and efficacy of these diagnostic methods.

Main Methods:

• Twenty-seven symptomatic platinum refinery workers and nine hyperresponsive controls underwent SPTs and BPTs using methacholine and hexachloroplatinic acid.
• Serial dilutions of hexachloroplatinic acid (10(-2)-10(-8) mol/l) were used for platinum salt testing.
• Specific airway conductance was measured to assess bronchial reactions.

Main Results:

• Twenty-three workers were identified as allergic to platinum salts, with 22 showing a significant drop in specific airway conductance during BPTs.
• Four workers had positive BPTs despite negative SPTs, indicating potential underdiagnosis with SPT alone.
• SPTs correlated with BPTs for platinum salt (rs = 0.50, p < 0.023), but no correlation was found with methacholine responsiveness.
• Adverse effects from platinum salt SPTs and BPTs were rare and absent in those with negative skin reactions.

Conclusions:

• Bronchial provocation tests with platinum salts are valuable for diagnosing occupational asthma in workers with symptoms but negative skin tests.
• BPTs should be considered in the diagnostic workup for suspected platinum salt-induced occupational asthma.
• Current diagnostic approaches may underestimate the prevalence of platinum salt allergy in refinery workers.