Chronic hives - Causes of chronic hives

Skin sensitivity > Chronic hives causes

Urticaria, also known as hives, appear as pink-red welts (wheals) on the skin and are usually itchy. Generally the causes of chronic hives are allergic reactions triggered by food, chemicals, physical stimuli or drugs.

On many occasions the causes are not known or idiopathic.

Hives is considered chronic when the swelling and redness persists or recurs for more than six weeks. The lesions of chronic hives are pink-red and appear as well-marked raised swelling. The lesions may appear round, oval or as generalized raised plaques. Some papules may be disappearing while new ones appear. In chronic hives this may go on for days together. Scratching causes new papules to appear.  In some individuals chronic allergy may resolve after a few weeks whereas in some individuals it may last or recur for years. Image describing the role of mast cells
in an alleric reactions in chronic hives

The causes behind chronic hives formation

The immune system is behind the allergic reactions resulting in hives. Our body's immune system being a system of biological structures and processes, is responsible for detecting a wide variety of invading pathogens, from viruses to parasitic worms and providing protection from them. The immune system has to distinguish the invaders from the organism's own healthy tissue and also other harmless substances. Inflammation is the first response on encountering infecting pathogens and causes increased flow of blood to the affected tissue which in turn causes redness, swelling, warmth, itching and pain.

Mast cells are resident cells of several types of tissues like connective and mucous tissues. They contain many granules rich in histamine, cytokines and heparin and regulate the immuno-inflammatory response. When activated mast cells rapidly release preformed mediators from granules like histamine, serine proteases, serotonins and heparin; various hormonal mediators like newly formed  lipid mediators, cytokines and Eosinophil chemotactic factor are also released into interstitial spaces.  Histamine by activating the endothelium and dilating capillary venules causes plasma to leak into interstitial spaces. This in turn causes edema, reddening, warmth, itching and pain. A cascade of other immune reactions follow to eliminate the pathogen.

However in some persons the immune system may get sensitized to harmless substances and set off allergic reactions. When the immune system mistakenly recognises the body's own tissues or other harmless substances as invaders, the mast cells release histamine and other chemicals and cause allergic reactions culmulating into chronic hives papules. Certain chemicals released in this process sensitize nerve endings making the affected area sensitive and itchy.

Allergins are causes of chronic hives in prone individuals

• Some drugs and medicines are causes (penicillin, sulfa drugs).
• Many chemicals, pesticides and detergents are causes of hives.
• Marine and fresh water foods like fish, lobsters and shellfish.
• Foods of animal origin like egg and milk are causes allergy in some individuals.
• Plant foods like peanuts, brazelnuts, walnuts and certain vegetables are the reasons.
• Animal dander, dust and dandruff.
• Insect bites, insect stings and insect waste (bedbug bites, mite bites, mosquito bites, scabies).
• Pollen, husk, bran and other plant products.
• Mental stress and emotional disturbances.
• Exposure heat or extreme cold.
• Exposure to sun.
• Exercise and perspiration.
• Many infections and diseases like lupus, thyroid disease, other autoimmune diseases, herpes and leukemia are causes for hives.
• Helicobacter pylori may function as a trigger of chronic hives.

Chronic idiopathic hives and autoimmunity

Many of the chronic cases of hives are idiopathic i.e. have no known causes. They are mostly due to autoimmunity. They have been found to be associated with other autoimmune diseases. About 33% of the patients with chronic idiopathic hives were found to have functional autoantibodies.

"If the conditions are affecting the throat, inner mouth or inner throat an emergency situation of life threatening respiratory stress and anaphylaxis may follow and hospitalization is immediately required."

Whatever be the cause of these chronic hives, there are first and second generation antihistamines and corticosteroids available for control and treatment of papules.

Topics of interest:
Chronic hives treatment
Types of hives

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References:
1.Prussin C, Metcalfe DD (2003). "IgE, mast cells, basophils, and eosinophils". J Allergy Clin Immunol 111 (2 Suppl): S486–94. DOI:10.1067/mai.2003.120. PMID 12592295.
2.Novembre E, Cianferoni A, Mori F, Barni S, Calogero C, Bernardini R, Di Grande L, Pucci N, Azzari C, Vierucci A. hives and urticaria related skin condition/disease in children. Eur Ann Allergy Clin Immunol. 2008 May;40(1):5-13. PMID: 18700329.

Silver blue skin - Argyria - causes, symptoms and treatment

Bluish skin discoloration > Silver blue skin - Argyria

What is argyria?

The rare blue skin disorder, Argyria, is due to the presence of silver in the skin.

Argyria disease results from protracted excessive exposure or ingestion of metallic silver, silver salts and silver compounds. There are two types of argyria disease. Ingestion of silver salts and silver compounds for prolonged period causes generalized (universal) form of argyria ailment whereas continuous localized excessive contacts with silver and its compounds causes localized argyria disease, affecting only the parts of the body which are in direct contact with blue or blue grey skin discoloration.

Apart from skin, sclerae, conjunctiva, oral mucosa, tongue, other mucous membranes, nail beds, gums and internal visceral organs also may get affected with discoloration. Melis Palamar, MD et al have recorded that the content and color of the tears can be affected by argyria. A patient with bilateral black tears (melanodacryorrhea) was found to have bilateral argyrosis of the conjunctiva due to occupational inhalation of silver compounds.

Silver has a wide variety of uses as jewelry, silverware, dental fillings, antibacterial agent and light sensitive coating of photo films. There are many medical uses of compounds of silver as incorporation into wound dressings, as antiseptic applications and as disinfectants in medical appliances. There is a school of alternative medicine advocating the use of colloidal silver as a cure for many ailments like AIDS and dermatitis. However the efficacy of these colloidal compounds in medical treatment is still under dispute. Bluish skin discoloration
Image of generalized argyria [Image by Herbert Fred, Hendrik van Dijk/Images of Memorable Cases: Case 4/ http://cnx.org/content/m14962/1.3/(CC-BY 2.0)]

Argyria causes and risk factors

• Prolonged exposure to dust containing particles of this metal, as in silver mining causes argyria.
• Prolonged exposure of workers in factories manufacturing jewelry and silverware may cause this blue skin disorder.
• Dental fillings made of this metal causes argyria in some cases. Silver sutures used in surgeries were one of the causes of this blue skin disease.
• Prolonged use of medications, drugs and supplements containing silver, its compounds or colloidal silver causes this disease.
• Homemade concoctions with this metal for treating diseases may cause argyria.
• Nasal sprays, nose drops, topical applications, tattoo colors and acupuncture and piercing needles containing  compounds of this metal can cause localized argyria.
• Lee SM and Lee SH of Department of Dermatology, Yonsei University College of Medicine, Seoul, Korea, reported a case wherein use of silver nitrate (AgNO3) to treat oral ulcers for ten years had caused generalized argyria.
• In a study in Japan it was found that habitual use of a breath freshener coated with silver had caused this disorder in some people.

Symptoms of argyria

• On prolonged exposure to silver or its salts if there is blue  or blue-grey skin discoloration, it is a clear symptom of argyria.
• Gums getting blue grey discoloration is another symptom of argyria.
• Blue discoloration of skin of the hands and face turning darker on exposure to sunlight is another symptom of argyria.
• Normally symptoms of argyria do not develop immediately. Up to 1 mg of silver is found in human body. Symptoms of this blue discoloration usually occurs when there is accumulation of four grams. In some people the symptoms show up when there is twenty grams or more of this metal in the body.

Diagnosis of argyria

• Causes of blue skin discoloration can be due to different diseases and a differential diagnosis may be necessary to pinpoint this disease.
• If the blue or blue grey skin darken when exposed to sunlight it could be diagnosed as a case of argyria.
• Biopsy of the skin also reveals the presence of silver deposits as blue-brown-black granules, singly or in clusters in the basement membrane zone surrounding the sweat glands, sebaceous glands and surrounding connective tissues.
• Silver is generally detected in the granular material in X-ray microanalysis assay.

Argyria treatment and prevention

• The treatment of this disease starts with immediate stoppage of exposure and seeking medical help.
• The doctor may prescribe topical hydroquinone ointment to reduce the blue skin patches in the case of localized argyria.
• Laser treatment has been successfully carried out in some cases to reduce the intensity of argyria blue patches.
• In some people exposure to high levels of silver particles in air can cause breathing problems, throat irritation and lung  irritation. A qualified doctor must be approached for treatment.
• Similarly contact skin allergies may occur in some people on exposure to this metal and a dermatologist must be consulted for treatment.
• For this generalized blue disorder there is no successful treatment.
• Avoiding sun exposure and using sunscreen helps in preventing this skin discoloration getting worse.
• Chelation therapy and dermabrasion have been tried and found ineffective as treatment for argyria and in removing metal deposits from the body.
• For those working in factories manufacturing various products of silver, wearing protective gear may help in preventing this blue discoloration.
• Environmental Protection Agency (EPA) recommends that the concentration of silver in drinking water not exceed 0.10 milligrams per liter of water (0.10 mg/L) because of the skin discoloration that may occur.

Although silver blue skin pigment changes are permanent, argyria disease usually has no adverse effect on health. Topic of interest:
Stress and skin problems like rashes