Long-term tolerance and efficacy of venom immunotherapy after an episode of Crohn's disease and ankylosing spondylitis after up-dosing.

Hymenoptera stings can cause severe anaphylactic reactions in patients with an underlying Hymenoptera venom allergy (HVA). In such cases, venom immunotherapy (VIT) is a highly effective measure to prevent future anaphylaxis. The management of patients with a clear allergological indication for VIT and contraindications to VIT (e.g., autoimmune diseases) remains a clinical challenge. We report the case of a 54-year-old male gardener who experienced life-threatening anaphylaxis after being stung by wasps in the head and neck region. After confirmation of a Vespula venom allergy (VVA) by intradermal test and VV-specific serum IgE antibodies, VIT was started using a rush protocol. One month after reaching the maintenance dose, the patient experienced a worsening of his pre-existing Crohn's disease and ankylosing spondylitis. VIT was stopped, and the autoimmune diseases were treated with systemic steroids and sulfasalazine. As the patient wished to remain in his profession, and in view of the previous severe anaphylaxis, we restarted VIT after the autoimmune diseases had resolved, using a slower up-dosing protocol. This approach was tolerated without side effects, and the patient tolerated a sting challenge and several field stings without anaphylactic symptoms.