Oral provocation of patients allergic to sesquiterpene lactones with German chamomile tea to demonstrate possible systemic allergic dermatitis

Abstract

Background: Most patients with contact allergy to Asteraceae plants are patch test positive to sesquiterpene lactone mix (SLM). There are several reports among these patients of a flare-up of hand eczema after ingestion of food and beverages originating from Asteraceae plants.

Aim: To investigate whether German chamomile tea can elicit systemic allergic dermatitis.

Patients and methods: Individuals with or without contact allergy to SLM were patch tested with an extract of German chamomile tea. Six weeks later, they were provoked with capsules containing either freeze-dried German chamomile tea or placebo capsules containing lactose, in a double-blind, randomized study. A numerical rating scale (NRS) was used to ascertain the volunteers' opinion of their hand eczema status. The study individuals were examined to detect a possible flare-up of healed patch test reactions to chamomile.

Results: None of the subjects had a flare-up of healed patch test reactions. According to the NRS, SLM-positive individuals experienced a significant worsening of hand eczema, independently of whether they received chamomile or lactose capsules.

Conclusion: No evidence suggestive of systemic allergic dermatitis was found.

Keywords: Asteraceae; Compositae; contact allergy; delayed hypersensitivity; flare-up; patch testing; pompholyx; sesquiterpene lactone mix; systemic allergic dermatitis; vesicular hand eczema.