Sarcoidosis Health Dictionary

A state in which the PLASMA calcium concentration is signi?cantly raised. The most important causes are HYPERPARATHYROIDISM, malignant bone disease and other (non-metastatic) cancers, and chronic renal failure. Less common causes include SARCOIDOSIS, MYELOMATOSIS, vitamin D overdosage (see APPENDIX 5: VITAMINS), hyperthyroidism (see THYROID GLAND, DISEASES OF), and immobilisation.

Signs and symptoms A general malaise and depression are common, with generalised muscular weakness, anorexia and vomiting. Disturbed renal function causes increased urine output and thirst, with calcium deposits eventually leading to renal stones. Primary bone disease may cause pain and weakness, with an increased incidence of fractures, and there may be gritty deposits of calcium in the eyes. Severe hypercalcaemia produces ANURIA, with confusion and COMA leading to death.

Treatment The patient should be rehydrated and a diuretic (see DIURETICS) given. Attention should then be focused on the underlying cause – usually a parathyroid adenoma or bone tumour – and surgical removal should produce complete clinical cure, provided that advanced renal disease is not already present.... hypercalcaemia

The characteristic histological test used for the diagnosis of SARCOIDOSIS. The test involves an intradermal injection of sarcoid SPLEEN tissue. If positive, non-caseating granulomata (see GRANULOMA) are seen at the injection site in 4– 6 weeks. A positive test is highly speci?c for sarcoid, but if negative, this would not be excluded.... kveim test

An aggregation of cells of a type associated with chronic inflammation. They usually occur as a reaction to certain infections, such as tuberculosis, or a foreign body, such as a suture, but they may develop for unknown reasons in conditions such as sarcoidosis.

A pyogenic granuloma is an excess of granulation tissue developing at the site of an injury to the skin or mucous membrane. (See also granuloma annulare; granuloma inguinale.)... granuloma

Redness of the skin due to dilatation of dermal blood vessels. It may be transient or chronic, localised or widespread, and it can be blanched by pressure. Erythema may be caused by excessive exposure to heat or ultraviolet light, or by in?ammation of the skin due to infection, DERMATITIS, and various allergic reactions – for example, to drugs. It may be emotional (e.g. as in ?ushing), mediated by the autonomic nervous system.

Erythema ab igne is a ?xed redness of the skin caused by chronic exposure to heat from a domestic ?re or radiator.

Erythema pernio (See CHILBLAIN.) Redness induced by spasm of the skin arterioles due to cold. It affects the hands, feet or calves in winter. The red swollen areas are cooler than normal.

Erythema nodosum A singular pattern of red, tender nodules occurring on the shins, often lasting several weeks. It may be caused by a streptococcal throat infection, primary tuberculosis, SARCOIDOSIS, or may be drug-induced.

Erythema multiforme is an acute allergic eruption of the extremities characterised by circular areas of erythema, purpura and blistering, which resolve over two or three weeks, caused by infections or drugs. In severe forms the mucous membranes of the eyes, mouth and genitalia may be involved.

Erythema infectiosum is an acute contagious disease of children caused by a parvo-virus (see PARVOVIRUSES). In young children a bright erythema of the face gives a ‘slapped cheek’ appearance.

... erythema

Underactivity of the PITUITARY GLAND. It can cause dwar?sm, delayed puberty, impotence, infertility, AMENORRHOEA, hypothyroidism (see THYROID GLAND, DISEASES OF), and hypoadrenalism. Causes include tumours, irradiation of the gland, SARCOIDOSIS, and necrosis associated with post-partum haemorrhage (Sheehan’s syndrome).... hypopituitarism

A method of diagnosing genetic abnormalities in a fetus using a small sample of tissue taken from the chorionic villi at edge of the placenta. Because the cells have the same chromosome makeup as those in the fetus, they can be used to detect genetic abnormalities. Chorionic villus sampling (CVS) is usually performed in the first 3 months of pregnancy in women who are at a higher-than-normal risk of having a child with a chromosomal disorder, such as Down’s syndrome, or a genetic disease, such as thalassaemia. Chromosome analysis of the villi cells takes place in the laboratory. CVS slightly increases the risk of miscarriage. choroid A layer of tissue at the back of the eye, behind the retina. The choroid contains many blood vessels that supply nutrients and oxygen to the retinal cells and to surrounding tissues in the eye. choroiditis Inflammation of the choroid. It is often caused by infections such as toxocariasis or toxoplasmosis, more rarely by sarcoidosis, syphilis, and histoplasmosis. It sometimes has no obvious cause. Treatment includes corticosteroid drugs for the inflammation, and antibiotic drugs for any causative infection.... chorionic villus sampling

Inflammation of the choroid. It is often caused by infections such as toxocariasis or toxoplasmosis, more rarely by sarcoidosis, syphilis, and histoplasmosis. It sometimes has no obvious cause. Treatment includes corticosteroid drugs for the inflammation, and antibiotic drugs for any causative infection.... choroiditis

A condition characterized by the eruption of red-purple, tender swellings on the legs.

The most common cause is a streptococcal infection of the throat, but the condition is also associated with other diseases, mainly tuberculosis and sarcoidosis, and may occur as a reaction to drugs, particularly sulphonamide drugs, penicillin drugs, and salicylate drugs. Sometimes there is no apparent cause.

Treatment of any underlying condition clears the swellings. Bed rest, analgesics, and, occasionally, corticosteroid drugs may be necessary.... erythema nodosum

A metallic element whose radioactive form is used in radionuclide scanning to detect areas of inflammation such as those that occur in cancers, abscesses, osteomyelitis, and sarcoidosis.... gallium

They may be local to the SKIN, or a manifestation of systemic disorders – inherited or acquired. Some major types are described below.

Others appear under their appropriate alphabetical headings: ACNE; ALBINISM; ALOPECIA; ALOPECIA AREATA; APHTHOUS ULCER; BASAL CELL CARCINOMA; BOILS (FURUNCULOSIS); BOWEN’S DISEASE; CALLOSITIES; CANDIDA; CHEILOSIS; CHEIRAPOMPHOLYX; DANDRUFF; DERMATOFIBROMA; DERMATOMYOSITIS; DERMATOPHYTES; DERMOGRAPHISM; ECTHYMA; ERYSIPELAS; ERYTHEMA; ERYTHRASMA; ERYTHRODERMA; ESCHAR; EXANTHEM; FUNGAL AND YEAST INFECTIONS; HAND, FOOT AND MOUTH DISEASE; HERPES GENITALIS; HERPES SIMPLEX; HERPES ZOSTER; IMPETIGO; INTERTRIGO; KELOID; KERATOSIS; LARVA MIGRANS; LICHEN; LUPUS; MADURA FOOT; MELANOMA; MILIARIA; MOLLUSCUM CONTAGIOSUM; MOLE; MYCOSIS FUNGOIDES; NAEVUS; ORF; PEDICULOSIS; PEMPHIGUS; PHOTOCHEMOTHERAPY; PHOTODERMATOSES; PITYRIASIS; PORPHYRIAS; PRURITUS; PSORIASIS; RINGWORM; ROSACEA; SARCOIDOSIS; SCABIES; SCLERODERMA; URTICARIA; VITILIGO; WARTS; XANTHOMATA.

Skin cancer Primary cancer is common and chronic exposure to ultraviolet light is the most important cause. BASAL CELL CARCINOMA is the most common form; squamous cell carcinoma is less common and presents as a growing, usually painless nodule which may ulcerate. Squamous cancer may spread to regional lymph glands and metastasise, unlike basal cell cancer. Occupational exposure to chemical carcinogens may cause squamous carcinoma – for example, cancer from pitch warts or the scrotal carcinoma of chimney sweeps exposed to coal dust in earlier centuries. Squamous carcinoma of the lip is associated with clay-pipe smoking.

Cancer may arise from the population of melanocytes of the skin (see MELANOCYTE; MELANOMA).

Apart from these three most frequent forms of skin cancer, various forms of cancer can arise from cells of the dermis, of which LYMPHOMA is the most important (see also MYCOSIS FUNGOIDES).

Lastly, secondary deposits from internal cancer, particularly from the breast, may metastasise to the skin.

Dermatitis and eczema These are broadly synonymous, and the terms are frequently interchangeable. Eczema is a pattern of in?ammation with many potential causes. Dermatitis is commonly used to suggest an eczema caused by external factors; it is a common pattern of in?ammation of the skin characterised by redness and swelling, vesiculation (see VESICLE), and scaling with intense itching and often exudation (weeping). Fissuring, thickening (licheni?cation – see LICHEN) and secondary bacterial infection may follow. Dermatitis can affect any part of the body. It may be genetically detemined or due to other ‘internal’ factors, such as venous HYPERTENSION in a leg, or stress. Often it is ‘external’ in origin – due to strong irritants or chemical allergens. (See also ALLERGY; ALLERGEN.) ATOPIC DERMATITIS is genetic in origin and usually begins in infancy. It may persist for years, and ASTHMA, allergic RHINITIS and conjunctivitis (see under EYE, DISORDERS OF) – ‘hay fever’ – may be associated. Atopic children tend to have multiple allergies, especially to inhaled allergens such as house-dust mite, cat and dog dander and pollens. Allergy to foods is less common but potentially more dangerous, especially if to nuts, when it can cause acute URTICARIA or even ANAPHYLAXIS. Atopic subjects are particularly prone to persistent and multiple verrucae (see WARTS) and mollusca (see MOLLUSCUM CONTAGIOSUM) and to severe HERPES SIMPLEX infections. (See also ATOPY.)

EXFOLIATE DERMATITIS (PITYRIASIS RUBRA)

Generalised exfoliation and scaling of the skin, commonly with ERYTHEMA. Drugs may cause it, or the disorder may be linked with other skin diseases such as benign dermatoses and lupus erythematosus (see under LUPUS). SUMMER POMPHOLYX is an acute vesicular eczema of the palms and soles recurring every summer. Inhaled allergens are a frequent cause. VENOUS (STASIS) DERMATITIS begins on a lower calf, often in association with PURPURA, swelling and sometimes ulceration. Chronic venous hypertension in the leg, consequent on valvular incompetence in the deep leg veins owing to previous deep vein thrombosis (see VEINS, DISEASES OF), is the usual cause. NEURODERMATITIS A pattern of well-de?ned plaques of licheni?ed eczema particularly seen on the neck, ulnar forearms or sides of the calves in subjects under emotional stress. IRRITANT CONTACT DERMATITIS Most often seen in an industrial setting (occupational dermatitis), it is due to damage by strong chemicals such as cutting oils, cement, detergents and solvents. In almost all cases the hands are most severely affected. ALLERGIC CONTACT DERMATITIS, in contrast, can affect any part of the body depending on the cause – for example, the face (cosmetics), hands (plants, occupational allergens) or soles (rubber boots). Particularly common allergens include metals (nickel and chromate), rubber addititives, and adhesives (epoxy resins).

Treatment Avoidance of irritants and contact allergens, liberal use of EMOLLIENTS, and topical application of corticosteroid creams and ointments (see CORTICOSTEROIDS) are central.... skin, diseases of

Sarcoidosis affecting the skin, in which purple, chilblain-like swellings appear on the nose, cheeks, or ears.... lupus pernio

see sarcoidosis. [C. P. M. Boeck (1845–1913), Norwegian dermatologist]... boeck’s disease

n. inflammation of a finger or toe caused by bone infection (as in tuberculous *osteomyelitis) or rheumatic diseases, such as spondyloarthropathy, psoriatic arthritis, or sarcoidosis or seen in infants with sickle-cell disease. The whole digit is swollen and may resemble a sausage (known as ‘sausage digit’). The diffuse swelling arises from the flexor tendon, its sheath, and adjacent soft tissue.... dactylitis

a rare syndrome in which *sarcoidosis is associated with swelling of the parotid and other salivary glands, uveitis, fever, and paralysis of the facial nerve. It can be treated with steroids but generally resolves spontaneously.... heerfordt’s syndrome

n. combined inflammation of the cornea and conjunctiva of the eye. Keratoconjunctivitis sicca is dryness of the cornea and conjunctiva due to deficient production of tears. It may be associated with systemic disorders, such as *Sjögren’s syndrome, systemic lupus, systemic sclerosis, and sarcoidosis.... keratoconjunctivitis

an acute form of *sarcoidosis characterized by fever, *erythema nodosum, enlarged lymph nodes near the inner border of the lungs, joint pain or inflammation, often involving the ankles, and *uveitis. Symptoms may resolve spontaneously after a few weeks or may need therapy with NSAIDs or low-dose corticosteroids. Recurrence may occur in a minority of patients. [S. Löfgren (1910–78), Swedish clinician]... löfgren’s syndrome

Many eye disorders are minor, but some can cause loss of vision unless treated. (See also cornea, disorders of; retinal detachment.)

Squint is sometimes present at birth. Rarely, babies are born with microphthalmos. Other congenital disorders that affect the eye are nystagmus, albinism, and developmental abnormalities of the cornea and retina.

Conjunctivitis is the most common eye infection and rarely affects vision. Trachoma or severe bacterial conjunctivitis can impair vision. Corneal infections can lead to blurred vision or corneal perforation if not treated early. Endophthalmitis (infection within the eye) can occur as a result of eye injury or infection elsewhere in the body.

Narrowing, blockage or inflammation of the blood vessels of the retina may cause partial or total loss of vision.

Malignant melanoma of the choroid is the most common cancerous tumour of the eye. Retinoblastoma is a cancerous tumour of the retina that most commonly affects children.

Various vitamin deficiencies (particularly of vitamin A) can affect the eye. This may lead to xerophthalmia, night blindness, or, ultimately, keratomalacia.

Uveitis may be caused by infection or an autoimmune disorder such as ankylosing spondylitis and sarcoidosis.

Macular degeneration of the retina is common in the elderly, as is cataract.

Glaucoma, in which the pressure inside the eyeball becomes raised, can lead to permanent loss of vision. In retinal detachment, the retina lifts away from the underlying layer of the eye.Ametropia is a general term for any focusing error, such as astigmatism, myopia, or hypermetropia. Presbyopia is the progressive loss with age of the ability to focus at close range. Amblyopia is often due to squint.... eye, disorders of

n. poisoning by beryllium or its compounds, either by inhalation or by skin contamination. Inhalation of fumes from molten beryllium causes an acute *alveolitis and is usually fatal. Subacute and chronic forms can result from extremely low levels of exposure to the powder and can produce granulomata in the skin or lungs very similar to those seen in *sarcoidosis. In the lungs, these lead to fibrosis, which can, however, be prevented by prompt use of oral corticosteroids. Although the incidence of berylliosis has been greatly reduced since the use of beryllium compounds in the manufacture of fluorescent light tubes was discontinued in Britain in 1948, new cases are still occurring.... berylliosis

disease of the *tubulointerstitium of the kidney. Acute interstitial nephritis (AIN) represents in many cases an allergic reaction to drugs (especially ampicillin, cephalexin, NSAIDs, allopurinol, and frusemide). AIN can also be associated with acute infections and autoimmune disease. Thirst and polyuria may be prominent, and renal function severely affected. In allergic cases, the use of steroids hastens recovery after the allergen has been removed. Chronic interstitial nephritis (CIN) is associated with progressive scarring of the tubulointerstitium, often with lymphocyte infiltration. Primary causes of CIN include gout, radiation nephropathy, sarcoidosis, *analgesic nephropathy, reflux nephropathy, chronic hypokalaemia and hypercalcaemia, and *Aristolochia-associated nephropathies. Management of CIN involves removal of the precipitating cause, where identified, and control of hypertension.... interstitial nephritis

(uveoparotid fever) n. inflammation of the iris, ciliary body, and choroid regions of the eye (the uvea) and swelling of the parotid salivary gland: one of the mani-festations of the chronic disease *sarcoidosis.... uveoparotitis