The outpost of our immune defences, the skin is home to sentinel cells that protect it from external attacks, whether bacterial, fungal, or viral. In case of an “attack”, the latter triggers its defence mechanism. When a mosquito bites you, your skin heats up and swells in response, not to the bite, but to the mosquito’s saliva. The body immediately identifies this foreign body and activates its immune defences by releasing histamine. It is, therefore, this reaction that creates the inflammation and swelling that follows. Histamine stimulates the nerve fibres responsible for this itching sensation.
Unlike allergies, which have more severe manifestations, this swelling occurs in everyone.