PGD2 inhibitors are primarily used in the treatment of inflammatory and allergic conditions, particularly those related to the respiratory system. They play a crucial role in managing diseases like asthma and allergic rhinitis by blocking the action of prostaglandin D2, a key mediator in the inflammatory response. By inhibiting PGD2, these compounds help reduce symptoms such as airway constriction, nasal congestion, and inflammation, providing relief to patients. Additionally, PGD2 inhibitors are being explored for their potential in treating other conditions like atopic dermatitis and certain types of hair loss, where PGD2 is known to contribute to the pathology. Their targeted action makes them a promising option for improving quality of life in individuals with chronic inflammatory disorders.