CHRONIC SPONTANEOUS URTICARIA, LOW HISTAMINE DIET AS A TREATMENT

Abstract

<h3>Introduction</h3> Chronic Spontaneous Urticaria (CSU) is defined as urticaria that persists longer than six weeks. It was previously known as Chronic Idiopathic Urticaria. The current mainstay treatments for CSU include antihistamines and immunomodulators. The exact pathogenesis of CSU remains unclear. Here, we discuss two patients treated for CSU who demonstrated persistently elevated histamine levels with normal tryptase suggesting a non-mast-cell-mediated histamine elevation. Both were responsive to low-Histamine diet (LHD) as a primary treatment. <h3>Case Description</h3> A 50-year-old male presented for CSU. The patient was placed on intramuscular and oral corticosteroids for his symptoms with minimal relief. Laboratory studies revealed an elevated histamine level of 5.1 ng/mL and a normal tryptase level of 7.1 mcg/L. The patient was placed on LHD and subsequently reported complete resolution of CSU. 38-year-old male presented for a pruritic skin rash diagnosed as CSU. The patient was previously placed on antihistamines and steroid cream. Laboratory studies revealed multiple elevated histamine levels greater than 6.0 ng/mL and normal tryptase levels of 6.5 and 7.7 mcg/L. The patient was placed on LHD with satisfactory resolution of symptoms. <h3>Discussion</h3> Persistently elevated histamine levels may contribute to CSU in a subgroup of patients who may be experiencing symptoms due to a non-mast-cell-mediated histamine elevation. Further research is needed to evaluate LHD as a primary treatment for CSU articulately in the presence of persistently elevated histamine.