Red, blotchy skin is a form of inflammation that arises from a variety of medical or environmental conditions. Various skin conditions like keratosis pilaris, eczema
, rosacea, and contact dermatitis can be the culprits of your blotchiness. The treatment for those red blotches on your skin depends upon the condition which has caused it in the first place. So, if they arise from keratosis pilaris caused by an overproduction of skin protein keratin that plugs up pores within hair follicles, topical retinoids may help sloughing off the excess keratin from clogging pores, thus improving the affected skin significantly, or corticosteroids act to reduce the inflammation. In the case of contact dermatitis (in which your skin reacts to substances such as soap or chemicals), to pinpoint substances that trigger the reactions is the solution to get rid of those red blotches. If the weather is extremely dry and cold, you can develop red skin blotches, particular on the face. Under these extreme weather conditions, your skin loses moisture, leading to dryness and reddening of the skin. Overexposure to the sun can also cause a breakout of your skin into those red blotches. In general, creams and lotions(containing vitamin D, glycolic acid, lactic acid, salicyclic acid, tretinoin, and urea) that keep your skin soft and moisturized consequently reduce the appearance of blotchiness. In some cases, skin blotchiness can be caused due to certain serious health conditions. To rule out any serious medical condition and arrive an appropriate treatment for your red blotches, obviously a diagnosis needs to be established so an in-person dermatologist's visit to have your arms and neck/chest area thoroughly examined is the first step.