1. The chemical and proteins
that the insect injects under your skin, produces an allergic reaction
[release of histamine] resulting in "Swelling"/"itching"
2. anti histamine tablets, elevation of the Leg, ICE, Vinegar,aloe vera
gel is ideal for symptomatic treatment.
3. It would be wise to seek medical attention if swelling is growing, along with blisters formation [since it might have become infected.]
PS: wear long sleeves and long trousers in near future during outdoor activities.