Children can develop rashes on their bodies for a variety of reason. Rashes can cover the entire body, or can be localised in one area, such as the underarms. Certain causes of underarm rashes in children are viral, while others are hereditary.
Psoriasis causes the cells in the skin to become overproductive, leading to the development of scaly crusts on the skin. Psoriasis can develop all over the body but can centralise around the underarms.
Chickenpox is a viral infection that causes a fever and small, blistery spots on the body, especially under the arms and around the chest.
Fifth disease starts out with flu-like symptoms and causes the body to develop a very red rash. This rash can appear under the arms and can be very painful.
Hives are caused by a histamine reaction in the body, which causes the skin to flare up with extremely itchy blisters. These blisters, when located under the arms, can be uncomfortable and irritating.
Measles causes a reddish-brown rash to spread from the face down to the chest and into the area of the armpits. It is accompanied by a fever and dry cough.