Anaphylaxis in Omani Patients: A Study from a Tertiary Care Center

Objectives: Anaphylaxis is an acute and potentially fatal allergic reaction. No studies have yet been conducted to evaluate the spectrum of anaphylactic reactions among Omani patients. As such, this study aimed to describe the clinical features, causes, investigation, and management of anaphylaxis among patients presenting to a tertiary care center in Oman.

Methods: This retrospective study took place between August 2005 and June 2020 at the allergy and immunology clinic of Sultan Qaboos University Hospital, Muscat, Oman. All patients diagnosed with anaphylaxis during the study period were included. Data were collected from electronic medical records.

Results: One hundred patients were diagnosed with anaphylaxis during the study period. Of these, 52.0% were male. The mean age was 15.9±16.2 years, with 70.0% aged < 18 years old. The eosinophil count ranged from 0.0-16.9 × 10⁹/L, with a mean of 0.8±2.2 × 10⁹/L and a median of 0.3 (0.1-0.6) × 10⁹/L. Total immunoglobulin (Ig) E levels ranged from 25-8706 kIU/L, with a mean of 935.1±1369.5 kIU/L and a median of 500.4 (186.0-972.5) kIU/L. The majority of patients had a family history of allergies (72.0%), and other had concomitant allergic conditions (66.0%). All were prescribed epinephrine (100%). The most common cause of anaphylaxis was food (65.0%). The second most frequent trigger was insect venom (32.0%). Most patients had one category cause (81.0%); two or more causes were present in 12.0% of patients. Clinical symptoms manifested most frequently as cutaneous (92.0%) and respiratory (85.0%). The majority of patients (87.0%) demonstrated the involvement of more than one bodily system. Mean total IgE levels were significantly higher in patients with concomitant presence of other allergic conditions (1193.8 kIU/L) than patients without another concomitant allergic disease (503.6 kIU/L; p =0.030). In addition, concomitant allergic disease is significantly higher in patients < 18 years of age (75.4%) compared to patients > 18 years of age (45.2%; p =0.010).

Conclusions: Due to its life-threatening nature, knowledge of the epidemiology and clinical features of anaphylaxis in different populations is necessary to deliver rapid treatment. This study found that the clinical features of anaphylactic patients in Oman were similar to those reported elsewhere. Further research is needed to determine the true incidence of anaphylaxis in Oman to minimize associated morbidity and mortality.