Thanks for posting your query.
I can understand your concern for your child. Such an itchy skin rash which appears in response to change in weather is either due to atopic dermatitis or due to hives.
Atopic dermatitis is a type of eczema in which the skin may be "super sensitive" to many irritants. In this the skin becomes extremely itchy and inflamed, causing redness, swelling, vesicle formation (minute blisters), cracking, weeping, crusting, and scaling.
Diagnosis can be confirmed by examination and serum IgE levels. If atopic dermatitis is confirmed then treatment consists of topical steroid creams. Other than that, avoiding harsh soaps and cleansers, using only one brand of soap (Mild soaps like Dove or Aveeno are fine), preventing scratching or rubbing whenever possible, protecting skin from excessive moisture, irritants, and rough clothing, maintaining a cool, stable temperature and consistent humidity levels and limiting exposure to dust, cigarette smoke, pollens, and animal dander helps.
Moreover apply moisturizers like Sarna lotion after bathing just after patting with towel. In case of severe itching antihistaminic like Benadryl is helpful.
Hope that this information helps and hope that you will get better soon.
Wishing you good health.
Thank you doctor, her skin is very sensitive so this seems like it may be the culprit. We tried having it tested but her doctor said the only was was via a biopsy and advised against it.
We have been bathing her in dead sea salt and moisturizing her skin with a combo of castor oil and coconut oil. Both are antimicrobial antifungal. The skin has improved about 80% since I first wrote this. We'll stick with this as we try not to use medications unless completely necessary. Thank you for the information we appreciate it.