Key PointsQuestion
What caused unusual pruritic dermatitis after an occupational exposure in employees of a company that produced herbal medicines?
Findings
In this case series of 18 employees we hypothesized the causative agent to be Pyemotes ventricosus and an examination of the herbal specimens for ectoparasites confirmed the diagnosis. We found that changing the time when the herbs were weighed and abandoning gas fumigation containing methyl bromide led to a recurrence of an almost forgotten disease.
Meaning
This case series demonstrates the importance of examining environmental specimens for ectoparasites in cases of unexplained dermatoses.
Importance
Although Pyemotes species have been known to cause dermatitis, recent reports are rare. During the past 30 years, only 3 outbreaks of dermatitis caused by Pyemotes ventricosus have been reported.
Objective
To analyze the causative agent of skin changes in employees of a company that produced herbal medicines.
Design, Setting, and Participants
This case series includes 18 patients (8 men, 10 women; mean age, 44 years) who contracted unusual dermatitis after an occupational exposure in July and August of 2012 while working for a company that produced herbal medicines. The patients were examined at the Lower Silesia Regional Centre of Occupational Medicine in Wroclaw, Poland.
Exposures
Workers weighed and packed 1 part of the Helichrysum arenarium herb.
Main Outcomes and Measures
We hypothesized the causative agent to be P ventricosus. An examination of the herbal specimens for ectoparasites confirmed the diagnosis.
Results
Initially 16 employees developed pruritic skin changes. Skin lesions with pruritic vesicles on an erythematous base with surrounding swelling and edema were observed. Several employees also developed a flulike illness. After 44 days, 2 new employees presented with the same skin changes. The analysis of working conditions showed that the same part of the H arenarium herb was weighed and packed at that time.
Conclusions and Relevance
We found that changing the time when the herbs were weighed and abandoning gas fumigation containing methyl bromide resulted in the recurrence of an almost forgotten disease.