Thanks for posting question on HCM,
You are probably suffering from acute urticaria
perhaps due to sitting on grass ,start applying betamethasone
lotion twice a day after taking bath and oral antihistamine like Lortadine 10 mg 1 daily .if the response does not occur in 24 hours take one shot of inj decadron
4mg IV stat.
urticaria /hives; a vascular reaction of the upper dermis
marked by transient appearance of slightly elevated patches (wheals) which are redder or paler than the surrounding skin and often attended by severe itching; the exciting cause may be certain foods or drugs, infection, or emotional stress,cold,insect bite etc
Let me know if no response . I may ask for blood test
,urine test x ray chest to exclude any infection.
Hope this will alleviate your anxiety
Dr sher bhutto