Sex in Respiratory and Skin Allergies

Abstract

A bulk of literature demonstrated that respiratory allergy, and especially asthma, is prevalent in males during childhood, while it becomes more frequent in females from adolescence, i.e., after menarche, to adulthood. The mechanisms underlying the difference between females and males are the effects on the immune response of female hormones and in particular the modulation of inflammatory response by estrogens, as well as the result of the activity of various cells, such as dendritic cells, innate lymphoid cells, Th1, Th2, T regulatory (Treg) and B regulatory (Bregs) cells, and a number of proteins and cytokines, which include interleukin (IL)-4, IL-5, IL-10, and IL-13. As far as sexual dimorphism is concerned, a gender difference in the expression profiles of histamine receptors and of mast cells was demonstrated in experimental studies. A critical phase of hormone production is the menstrual cycle, which often is associated with asthma deterioration, as assessed by worsening of clinical symptoms and increase of bronchial hyperresponsiveness. In asthmatic woman, there is a high risk to develop more severe asthma during menstruation. The higher prevalence of asthma in females is confirmed also in the post-menopause age, but the underlying mechanisms are not yet understood. In pregnancy, asthma may worsen but may also improve or remain unchanged, with no significant difference in frequency of these three outcomes. For allergic rhinitis, the available studies indicate, likewise asthma, a male predominance in prevalence in childhood that shifts to a female predominance in adolescence and adulthood, but further investigation is needed.

Chronic prurigo: A retrospective study of 168 cases

“…This is, however, inconsistent with our findings of increased prevalence of PCM in men. Notably, the sex distribution trend observed in AD is reversed in individuals over 65 years of age, with more elderly males affected than women . We therefore speculate that similar mechanisms may account for the high prevalence of PCM in males, a disease that also is common in the elderly.…”

“…In contrast, we found that males were more frequently affected by PCM than females (Table ). The modulation of immune responses by estrogen, a female hormone, has been well documented . Estrogen enhances type 2 responses and promotes increased production of Th2 cytokines, including IL‐4, IL‐5 and IL‐13 .…”

“…The modulation of immune responses by estrogen, a female hormone, has been well documented . Estrogen enhances type 2 responses and promotes increased production of Th2 cytokines, including IL‐4, IL‐5 and IL‐13 . Atopic dermatitis (AD), for example, a well‐known Th2‐mediated inflammatory condition, predominantly affects women .…”

“…11 Estrogen enhances type 2 responses and promotes increased production of Th2 cytokines, including IL-4, IL-5 and IL-13. 11 Atopic dermatitis (AD), for example, a well-known Th2-mediated inflammatory condition, predominantly affects women. 12 This is, however, inconsistent with our findings of increased prevalence of PCM in men.…”

Mast cells—Good guys with a bad image?

“…The answers as to why men and women are differently vulnerable to MC-associated diseases are given by their different hormonal state, distinct histamine receptor expression, 101 and gender-dependent number and activity of MCs themselves. 108,109 It has been shown that MCs are receptive for hormonal stimuli, as they express estrogen and progesterone receptors.…”