Skin discoloration - D/D

40F Sudden onset 2 days ago when she was busy in jute processing. Itchy. No any h/o insect bite there (might be she couldn't notice).Only the upper right limb involved.

40yr m c/o rash over body only in evening with itching subsides its own after 4- 6hrs ,non diabetic wt is the diagnosis &t/t

29 y/o female. First developed a furuncle on thigh. Applied antibiotic cream for days. Furuncle did not develop any further, no pain but still red and swollen around area. A few days after, patient developed pruritic rash around area. Rash spreading around thigh and lower leg. Any guess what it is? Staph infection?

7 year old boy with complains of itching and watering and both eyes since 3 to 4 months diagnosis ? signs seen in this picture?

3yrs pediatric pt has swelling of penis all of sudden . he is not co operative to tell any history . but accor. to his parents he can't allow to touch . what are the d/d ? which medication should preffered?