Cross-Desensitization To Goat and Sheep Milk Protein In Cow’s Milk Protein Desensitized Patients
Rationale: Over 90% cow’s milk protein (CMP) allergic patients cross react to both goat’s milk protein (GMP) and sheep’s milk protein (SMP) due to shared kappa-casein protein epitopes. We investigated whether CMP allergic patients who have been successfully fully desensitized in an oral immunotherapy (OIT) program would be able to consume GMP and SMP without an allergic reaction.
62 patients (age 4-29 years) who completed an OIT program and were consuming 240 ml of cow’s milk and dairy foods daily were evaluated. Skin puncture testing (SPT) followed by oral challenge of 3000mg GMP and 6000 mg SMP was then performed.
Positive SPT’s to GMP and SMP were identified in 34/53 and 33/53 respectively. 2/62 (3.2%) of patients challenged with GMP reacted. One patient had mild GI symptoms which resolved without treatment and the second experienced a systemic reaction which required treatment with epinephrine. 2/60 (3.3%) challenged with SMP reacted with mild conjunctivitis treated with antihistamines. The reactions to GMP and SMP occurred after one hour following the last dose and to relatively large amounts of protein.
Over 95% of desensitized CMP-allergy patients are also cross-desensitized to GMP and SMP. However, a supervised oral challenge to GMP or SMP should be performed before these patients are allowed to consume these related milk proteins.