D1.84 - IgE-mediated allergy to chlorhexidine: case report

Background: Chlorhexidine (CHX) is a commonly used antiseptic and disinfectant in the health-care setting. Allergy to CHX is a rare, but can be life-threatening condition.

Cas report: Patient, 59 years old, was preparing for prostate biopsy. Day before biopsy, he started to take ciprofloxacin and metronidazole orally. During the procedure of biopsy, a lubricant containing lidocaine and CHX was applied and 15 minutes later patient felt an itch of the neck and hives of the upper part of the body with angioedema of the tongue and throat. Blood pressure was normal, as long as saturation of oxygen. Patient received anti-allergic therapy and symptoms resolved. 6 month later another biopsy is planned. Patient received diclofenac injection 45 minutes before the procedure, and again the same lubricant containing lidocaine and CHX was applied. 10 minutes later patient felt the same symptoms and received anti-allergic therapy. The patient was referred to an allergist. Drug provocation tests with ibuprofen, paracetamol, ciprofloxacin were performed and were negative, as well as latex skin prick test and latex specific IgE, also negative. The patient was advised to determine CHX specific IgE, but he failed to do so. Three years later patient used a liquid containing CHX and sodium fluoride for mouth washing due to aphthae. 15 minutes later patient felt itch of the hole body and hives on the hands, neck and felt swallowing difficulties. He was transferred to an Emergency center where edema of the tongue, uvula and the throat was registered, as well as hives on the neck, torso and arms. He was normotensive, eupneic, received corticosteroids and antihistamines parenterally and a few hours later was discharged. A month later, patient was referred to an allergist, who performed drug provocation test to lidocaine which was negative. Additionally, an immunologist tested for CHX specific IgE using ImmunoCAP method and determined 1,62 kUA/L, positive.

Conclusion: Diagnosis of CHX allergy is important, because the patient can have an accidental re-exposure to the allergen.