I have what I guess can be described as a mild case of bed bugs in one of my cars, weird I know but in the process of taking care of it. Anyway I get bites around my elbows and it gets really itchy and bothersome for almost a week. What I found works wonders for me is simply taking 1000 mg of motrin once a day. I had a huge welt that looked swollen and red and taking motrin calmed it down and made it stop itching for almost a full day at a time.
An OTC antiseptic medication can be used for skin irritation that may then develop into an infection. As a precaution, do not use creams on broken or infected skin. If you have already been scratching, do not use these products on any raw or weeping areas. If you see signs of a skin infection, such as redness, don't use these creams in that area, and call your doctor.
Bed bug bites typically appear in groups of three, called the "breakfast, lunch, and dinner" pattern. Each victim's reaction to bed bug bites is unique. Some may have a slight reddening of the skin. Others may have a more severe reaction, causing a raised, itchy rash. A raised rash may obscure the individual bites, making it challenging to identify. Sometimes, bites and lesions can throb and become very painful for days after the bugs bit you.
The size of bed bug bites varies with a number of different factors. Bed bugs inject an anti-coagulant along with their saliva when they pierce the skin to take a blood meal. This anti-coagulant is mostly responsible for how a person reacts to the bite and determines the size of the bug’s bite. Since people will have various sensitivities to the bed bug’s bite, the size of the bite will vary, as well. Another factor that influences the size of a bed bug reaction is the number of times a person is bitten. Bite reactions of people bitten many times are also variable, and their response may be either more or less intense as the number of bites increases.