Causes of Hives In Adults – Diagnostic City

Hives(Urticaria)

Urticaria commonly known as hives, is an acute eruption of recurring, pruritic, papules and plaques. It is self limiting rash but in many patients it becomes chronic and relapsing. It is due to local increase in permeability of capillaries and small vanules. A large number of imflammatory mediators including leukotrienes, prostaglandins and chemotactic factors can play a role but a key role as a mediator is played by histamines derived from skin mast cells. Local mediators may be induced by immunological or non-immunological mechanisms. It affects the quality health of the pateint.

Causes of Hives(Urticaria)

The causes of urticaria is idiopathic. It is usually caused by comsuming certain food such as nuts, sesame seeds, shellfish, dairy products and may be caused due to some drugs such as penicillin, contrast media, non-steroidal anti-inflammatory drugs(NSAIDS), angiotensin-converting enzyme inhibitors(ACE-i). The common cause of urticaria include insect bites, contact(e.g.Latex), viral or parasitic infections, autoimmune, and hereditary. In some cases it may be angio-oedema.

Symptoms of Hives(Urticaria)

An urticarial rash is in the form of weals: pruritic, raised oedematous papules and plaques. It is usually erythematous with a pale centre. In urticarial rash scaling is always absent. Individual lesions appear on any part of the skin within a few minutes and will be resolved within 24 hours. New lesions can appear anywhere on the skin. If the patient is dermographic, a firm but gentle, scratch of the skin with an orange stick will produce a linear weal within 5-10 minutes. It can be associated with angio-oedema, where they cause swelling of lips, tongue, and around the eyes. The presentation of urticaria include

Swelling of superfacial dermis, raising the dermis
Itchy wheals
Angioedema which involves the deeper swelling of dermis and subcutaneous tissues.
Swelling of lips and tongue
Anaphylactic shock
Bronchospasm
Facial and laryngeal oedema
Hypotension

Diagnosis for Hives(Urticaria)

Biopsy is not usually indicated for diagnosis as the features are nonspecific, with oedema and a mixed dermal inflammatory infiltrate. Histology of urticaria shows the possibility of urticarial vasculitis. If there is a history of new drugs, drug reactions should be considered.

In urticarial vasculitis, lesions may persist for more than 24 hours and it may resolve with brusing. If the local application of products preceded with rash, contact urticaria should be considered.

If there is a history of contact with mosquitoes, bed bugs, or fleas, papular urticaria is possible.

Treatment of Hives(Urticaria)

Acute urticaria is normally triggered by drugs, food or infections. It can be resolve in less than 1 month. Treatment is symptomatic with high-dose of antihistamines.

Chronic urticaria may lasts longer than 6 weeks and in some cases it may co ntinue for many years. It is idiopathic in many cases and investigations are not indicated. Treatment can be possible with single or combination of high-dose antihistamines and avoidance of associated triggers. The triggers may include sun exposure, pressure, and exercise. The addition of H2 blockers such as cimetidine and tricyclic antidepressant doxepin can also be helpful.

Medication for Hives

Oral antihistamines are used to cure urticaria, that are classified into

Nonsedative antihistamines(e.g ceterizine, laratadine)
Sedative antihistamines(e.g. Chlorpheniramine, hydoxyzine)

These medicines block histamines receptors producing an anti-pruritic effect. These are also useful for type-1 hypersensitivity reactions and eczema. Especially sedative antihistamines are used for children.

Corticosteroids are used for severe acute urticaria and angioedema. Oral corticosteroids can be classified as

Mildly potent(e.g.hydrocortisone)
Moderately potent(e.g.clobetasone butyrate(Eumovate))
Potent(betamethasone velerate(Betnovate))
Very potent(Clobetasol propionate(Dermovate))
Oral steroids include Prednisolone
Applied 30grams per tube that is enough to cover the whole body once.

These medicines have anti-inflammatory and anti-poliferative effects. These are useful for immune and allergic reactions, inflammatory conditions of skin, vasculitis, blistering diseases and connective tissue disorders.

Side effects of medicines such as antihistamines and corticosteroids