This seems be an allergic reaction. Allergies are common in the summer months. Allergy is caused by an oversensitive immune system, which leads to a misdirected immune response.
Common allergens include pollen, mold, pet dander, and dust. Food and drug allergies are common. Allergic reactions can also be caused by insect bites, jewelry, cosmetics, and other substances.
Some people have allergy-like reactions to hot or cold temperatures, sunlight, or other physical stimuli. Sometimes, friction (rubbing or vigorously stroking the skin) will cause symptoms.
Short-acting antihistamines available over-the-counter can alleviate the itching.
Hydrocortisone cream (1%) is available without a prescription and may soothe many rashes. You do not really ned to apply it since the rash subsides on its own.
" Up to 40 percent of women with asthma find their symptoms worsen just before and during menstruation. Progesterone, a female hormone, rises sharply and then drops abruptly towards the end of the menstrual cycle, just before menstruation begins, although scientists don't understand exactly how progesterone affects asthma".
This could also be the cause for allergic skin reactions, since asthma too has an allergic component in its causation.