If you had herpes infection behind the leg, itself this could be the reason for the
sunburn like sensation. You might be having sharp, burning pain, extremely sensitive to touch, and temperature change. Treatment will depend on the type of pain. This includes anti depressants like serotonin or norepinephrine reuptake inhibitors and tricyclic antidepressants, anticonvulsants, pain killers like tramadol, TENS, spinal cord or peripheral nerve stimulation.