Intralesional methotrexate for treatment of alopecia areata: clinical evaluation and effect on lesional TNF alpha

Abstract

lopecia areata is an acquired autoimmune disease, affecting approximately 2% of the world population. It is formed of non-cicatricial patches of hair loss. It is commonly associated with other autoimmune diseases, among which atopy and autoimmune thyroiditis are the most common. Alopecia areata can appear at any time, and it significantly impairs the patient’s quality of life. The pathogenesis of AA is not completely clear, although it is well-established that genetic and environmental factors contribute to its development. Autoimmune attack of the hair follicles due to the collapse of the immune privilege (IP) of the anagen hair bulb is considered to play the main role in AA development. Studies have shown increased TNF-α in patients by affected by alopecia areata patients’ serum and tissue. It has been found to induce formation of club-like hair follicle, similar to catagen stage. Methotrexate was found to decrease TNF-α level by releasing adenosine in extracellular space and inhibiting immune cells.