Risk factors for premenstrual asthma: a systematic review and meta-analysis.

INTRODUCTION: Asthma in women can deteriorate in specific phases during the menstrual cycle. Deterioration in the premenstrual phase (increase in symptoms or deterioration in peak flow measurements) is known as premenstrual asthma. The etiology remains mostly unknown. Areas covered: This paper systematically reviews risk factors for premenstrual asthma. Medline, Embase, CINAHL, Scopus, Web of Science, LILACS and secondary sources were searched. The selection criteria were met by 20 articles. Expert commentary: Women with pre-menstrual asthma are older, have more severe asthma, a higher body-mass index, a longer duration of asthma and a greater likelihood of aspirin sensitive asthma. They more often have dysmenorrhea, premenstrual syndrome, shorter menstrual cycles, and longer menstrual bleeding. The role of hormone levels and systemic inflammation remains unclear.