Urticaria is also known as hives or nettle rash, is a group of disorders characterized by eruption of wheals which are transient, itchy, well-demarcated, superficial, erythematous or pale swellings of the dermis. Urticaria is a common problem with cumulative lifetime prevalence of 1 -5 % and female preponderance. The size of wheal may range from a few millimeters to large confluent lesions. Lesions are very itchy and provoke rubbing rather than scratching .acute urticarea may present as an anaphylactic reaction. Usually urticaria is precipitated by the intake of certain drugs and stings of insects. Urticaria can be classified on the basis of trigger factors.
Wheals erupt spontaneously and subsides with in a few minutes to hours and do not persist beyond 24 hours. Acute urticarea resolves within 2weeks. Chronic urticaria persists for more than 6weeks.Episodic urticaria is recurring acute urticaria. Allergic mast cells are the major effector cells of urticaria.The pathogenesis of acute urticaria involves the interaction of an allergen with specific IgE antibodies on mast cells. This result in vasodilatation, wheal formation and clinical manifestations.Eosinophils play a major role in persistence of wheals.
- Drugs like pencillin, cephalosporins, insulin, vaccines.
- Insect stings by bee, wasps etc.
- Latex in rubber products such as gloves.
- Inhalants such as pollens, animal dander, mould spores and house dust.
Non allergic causes -----direct histamine release from mast cells occurring due to some drugs like aspirin,morphine,iodine based dyes etc.Some foods like peanuts, cheese ,meat ,tomatoes ,pineapple ,strawberries,shellfish,prawns&some food preservatives can also cause this.
- Idiopathic-no cause can be identified.
It is difficult to determine the cause of chronic urticaria.50% are classified as chronic autoimmune urticaria and have circulating auto antibodies in their sera. Remaining cases are labeled as chronic idiopathic urticaria although there are some known aggravating factors such as foods, inhalants, infections.
It occurs following contact with substances like cosmetics, foods, medicaments etc.There can be immunological contact urticaria due to type 1hypersensitivity.Non immunological contact urticaria are mediated by prostaglandins. Lesions appear within minutes to hours of contact with provoking substances. In Immunological contact urticaria lesions occur on secondary exposure to the substance in pre sensitized individuals.
It usually has a chronic cause and is induced by a physical stimulus Types-
- Dermographism----stroking of skin produces linear lesions or lesions assume the shape of the eliciting stimulus with surrounding erythema [redness].
- Pressure urticaria results from sustained pressure on some parts of body. It can be immediate or delayed.
- Cholinergic urticaria occurs as a consequence to sweating following exercise ,hot bath and is characterized by very small eruptions.localised heat urticaria appear at sites of contact with heat.
- Adrenergic urticaria appears as multiple small wheals and is induced by stress.
- Exercised induced anaphylaxis – It starts with itching, followed by urticaria and angioedema.
- Solar urticaria appears following exposure to sun. Wheals develop over photo exposed parts within minutes of exposure.
- Aquagenic urticaria happens on contact with water.
- Cold urticaria occur on exposure to cold
- Vibratory angioedema is induced by vibratory stimuli.
Angioedema is characterized by diffuse swelling of eyelids, lips, genitalia and may be associated with anaphylaxis. Angioedema involves deeper dermis ,subcutaneous and sub mucosal tissue and is characterized by localized ,episodic,nonerythematous and mildly itchy but painful swelling of skin of eyelids,lips,upper respiratory tract and genitalia.It can be associated with symptoms of dyspnoea and dysphagia which may be life threatening. Angioedema with wheals is a type 1 hypersensitivity reaction triggered with in minutes by foods [e.g.: fish, shellfish and nuts], contact with latex or drugs.angioedema without wheals is associated with C I -esterase inhibitor deficiency which can be hereditary or acquired.
From the above description of urticaria with its classification on the basis of causation it is very evident that all those implicated causative factors are just triggers of urticaria or angioedema. The real cause is individual predisposition to get urticaria on exposure to these triggers. Even the common drugs for acute infections like fever, cough etc produce urticaria in prone people. Homeopathy addresses both issues very effectively in acute and chronic states. Homeopathic constitutional medicines and mother tinctures are devoid of any side effects. A few homeopathic medicines are listed here: Apis mel, calcarea carb, lycopodium, natrum mur, rhus tox, sulphur, and silicia.Angioedema also can be effectively managed by homeopathic medicines in acute and chronic states if anaphylaxis symptoms are not there. Anaphylaxis [respiratory and swallowing difficulty associated with angioedema] requires emergency hospital care.