Urticaria  commonly referred to as hives, is a kind of skin rash notable for pale red, raised, itchy bumps. Hives may cause a burning or stinging sensation They are frequently caused by allergic reactions; however, there are many nonallergic causes. Most cases of hives lasting less than six weeks (acute urticaria) are the result of an allergic trigger. Chronic urticaria (hives lasting longer than six weeks) is rarely due to an allergy.
The majority of chronic hives cases have an unknown (idiopathic) cause. In perhaps as many as 30–40% of patients with chronic idiopathic urticaria, it is caused by an autoimmune reaction.
SULPHUR 200- Sulphur is the top remedy for urticara. There is aggravation at night. The rash becomes chronic
ASTACUS FL. 30-Another excellent remedy for urtaria.Irritation is more at night in the warmth of bed. Chronic urticaria. Liver diseases generally present
APIS MEL  30—Sudden puffing of the whole body. , swellings like bites of honey bee. Stinging and burning pain
CHLORALOSUM 1X—If apis does not relieve , give four doses of this remedy ina day. It is a very successful remedy. It has red eruptions like measles with intense itching and sleeplessness
NATRU MUR 200—If there is constipation along with this disease and the patient is emaciated with an earthy complexion. Urticaria after quinine or after suppression of malaria
RHUS TOX  30—Urticaria with restlessness and burning. Itching is better by the warmth of bed. Uncovering aggravates
SEPIA 200—Urticaria worse in the open air and better in  a warm room , after taking milk
THYROIDINUM 3X- A specific remedy for urticaria. More the swelling , more the area of infection

URTICA URENS 1X—Intense and intolerable itching of skin. Face is swollen with the rash. Irresistible scratching . This can be applied externally