Refractory chronic spontaneous urticaria management in resource-poor settings: A critical appraisal

Urticaria is characterized by the occurrence of wheals, angioedema, or both. When urticaria duration is >6 weeks, it is known as chronic urticaria (CU). CU is classified as spontaneous (CSU) and inducible (CIndU). When the clinical course has no definite physical eliciting factor involved and shows a spontaneous course, it is described as CSU, and when a physical eliciting factor is present, it is called CIndU. CIndU is further subclassified as symptomatic dermographism, cold urticaria, delayed pressure urticaria, solar urticaria, heat urticaria, and vibratory angioedema, as well as cholinergic urticaria, contact urticaria, and aquagenic urticaria. CU patients can simultaneously present with more than one form of CU, especially CIndU. The management of CSU commences with the second-generation H1 anti-histamine. A few CSU patients do not respond to a single dose of 2 nd- generation anti-histamine; then, the dose is escalated to 4 fold the usual dose. About 10–50% patients do not respond to even 4-fold increased doses of which end up necessitating the repeated use of oral corticosteroids to control disease exacerbations is classified to have refractory CSU. Various drugs and biologics are in the armamentarium of dermatologists and allergologists; however, there are financial constraints in the developing world in resource-poor settings. Omalizumab, dupilumab, remibrutinib, and cyclosporine are the agents that are used in refractory urticaria. The financial burden of these agents restricts patients in poor settings to use for long-term therapy. The agents such as methotrexate, tofacitinib, and mycophenolate mofetil have been used with success anecdotally. However, azathioprine has shown a ray of hope in refractory urticaria patients, which may be an alternative in difficult-to-treat cases of CSU.