Cause Asthma runs in families, so that parents with asthma have a strong risk of having children with asthma, or with other atopic (see ATOPY) illnesses such as HAY FEVER or eczema (see DERMATITIS). There is therefore a great deal of interest in the genetic basis of the condition. Several GENES seem to be associated with the condition of atopy, in which subjects have a predisposition to form ANTIBODIES of the IgE class against allergens (see ALLERGEN) they encounter – especially inhaled allergens.
The allergic response in the lining of the airway leads to an in?ammatory reaction. Many cells are involved in this in?ammatory process, including lymphocytes, eosinophils, neutrophils and mast cells. The cells are attracted and controlled by a complex system of in?ammatory mediators. The in?amed airway-wall produced in this process is then sensitive to further allergic stimuli or to non-speci?c challenges such as dust, smoke or drying from the increased respiration during exercise. Recognition of this in?ammation has concentrated attention on anti-in?ammatory aspects of treatment.
Continued in?ammation with poor control of asthma can result in permanent damage to the airway-wall such that reversibility is reduced and airway-narrowing becomes permanent. Appropriate anti-in?ammatory therapy may help to prevent this damage.
Many allergens can be important triggers of asthma. House-dust mite, grass pollen and animal dander are the commonest problems. Occupational factors such as grain dusts, hard-metals fumes and chemicals in the plastic and paint industry are important in some adults. Viral infections are another common trigger, especially in young children.
The prevalence of asthma appears to be on the increase in most countries. Several factors have been linked to this increase; most important may be the vulnerability of the immature immune system (see IMMUNITY) in infants. High exposure to allergens such as house-dust mite early in life may prime the immune system, while reduced exposure to common viral infections may delay the maturation of the immune system. In addition, maternal smoking in pregnancy and infancy increases the risk.
Clinical course The major symptoms of asthma are breathlessness and cough. Occasionally cough may be the only symptom, especially in children, where night-time cough may be mistaken for recurrent infection and treated inappropriately with antibiotics.
The onset of asthma is usually in childhood, but it may begin at any age. In childhood, boys are affected more often than girls but by adulthood the sex incidence is equal. Children who have mild asthma are more likely to grow out of the condition as they go through their teenaged years, although symptoms may recur later.
The degree of airway-narrowing, and its change with time and treatment, can be monitored by measuring the peak expiratory ?ow with a simple monitor at home – a peak-?ow meter. The typical pattern shows the peak ?ow to be lowest in the early morning and this ‘morning dipping’ is often associated with disturbance of sleep.
Acute exacerbations of asthma may be provoked by infections or allergic stimuli. If they do not respond quickly and fully to medication, expert help should be sought urgently since oxygen and higher doses of drugs will be necessary to control the attack. In a severe attack the breathing rate and the pulse rate rise and the chest sounds wheezy. The peak-?ow rate of air into the lungs falls. Patients may be unable to talk in full sentences without catching their breath, and the reduced oxygen in the blood in very severe attacks may produce the blue colour of CYANOSIS in the lips and tongue. Such acute attacks can be very frightening for the patient and family.
Some cases of chronic asthma are included in the internationally agreed description CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) – a chronic, slowly progressive disorder characterised by obstruction of the air?ow persisting over several months.
Treatment The ?rst important consideration in the treatment of asthma is avoidance of precipitating factors. When this is a speci?c animal or occupational exposure, this may be possible; it is however more di?cult for house-dust mite or pollens. Exercise-induced asthma should be treated adequately rather than avoiding exercise.
Desensitisation injections using small quantities of speci?c allergens are used widely in some countries, but rarely in the UK as they are considered to have limited value since most asthma is precipitated by many stimuli and controlled adequately with simple treatment.
There are two groups of main drugs for the treatment of asthma. The ?rst are the bronchodilators which relax the smooth muscle in the wall of the airways, increase their diameter and relieve breathlessness. The most useful agents are the beta adrenergic agonists (see ADRENERGIC RECEPTORS) such as salbutamol and terbutaline. They are best given by inhalation into the airways since this reduces the general side-effects from oral use. These drugs are usually given to reverse airway-narrowing or to prevent its onset on exercise. However, longer-acting inhaled beta agonists such as salmeterol and formoterol or the theophyllines given in tablet form can be used regularly as prevention. The beta agonists can cause TREMOR and PALPITATION in some patients.
The second group of drugs are the antiin?ammatory agents that act to reduce in?ammation of the airway. The main agents in this group are the CORTICOSTEROIDS. They must be taken regularly, even when symptoms are absent. Given by inhalation they have few side-effects. In acute attacks, short courses of oral steroids are used; in very severe disease regular oral steroids may be needed. Other drugs have a role in suppressing in?ammation: sodium cromoglycate has been available for some years and is generally less e?ective than inhaled steroids. Newer agents directed at speci?c steps in the in?ammatory pathway, such as leukotriene receptor-antagonists, are alternative agents.
Treatment guidelines have been produced by various national and international bodies, such as the British Thoracic Society. Most have set out treatment in steps according to severity, with objectives for asthma control based on symptoms and peak ?ow. Patients should have a management plan that sets out their regular treatment and their appropriate response to changes in their condition.
Advice and support for research into asthma is provided by the National Asthma Campaign.
See www.brit-thoracic.org.uk
Prognosis Asthma is diagnosed in 15–20 per cent of all pre-school children in the developed world. Yet by the age of 15 it is estimated that fewer than 5 per cent still have symptoms. A study in 2003 reported on a follow-up of persons born in 1972–3 who developed asthma and still had problems at the age of nine. By the time these persons were aged 26, 27 per cent were still having problems; around half of that number had never been free from the illness and the other half had apparently lost it for a few years but it had returned.... asthma
Acute bronchitis is due to an acute infection – viral or bacterial – of the bronchi. This is distinguished from PNEUMONIA by the anatomical site involved: bronchitis affects the bronchi whilst pneumonia affects the lung tissue. The infection causes a productive cough, and fever. Secretions within airways sometimes lead to wheezing. Sometimes the speci?c causative organism may be identi?ed from the sputum. The illness is normally self-limiting but, if treatments are required, bacterial infections respond to a course of antibiotics.
Chronic bronchitis is a clinical diagnosis applied to patients with chronic cough and sputum production. For epidemiological studies it is de?ned as ‘cough productive of sputum on most days during at least three consecutive months for not less than two consecutive years’. Chronic bronchitis is classi?ed as a CHRONIC PULMONARY OBSTRUCTIVE DISEASE (COPD); chronic ASTHMA and EMPHYSEMA are the others.
In the past, industrial workers regularly exposed to heavily polluted air commonly developed bronchitis. The main aetiological factor is smoking; this leads to an increase in size and number of bronchial mucous glands. These are responsible for the excessive mucus production within the bronchial tree, causing a persistent productive cough. The increased number of mucous glands along with the in?ux of in?ammatory cells may lead to airway-narrowing: when airway-narrowing occurs, it slows the passage of air, producing breathlessness. Other less important causative factors include exposure to pollutants and dusts. Infections do not cause the disease but frequently produce exacerbations with worsening of symptoms.
Treatments involve the use of antibiotics to treat the infections that produce exacerbations of symptoms. Bronchodilators (drugs that open up the airways) help to reverse the airway-narrowing that causes the breathlessness. PHYSIOTHERAPY is of value in keeping the airways clear of MUCUS. Cessation of smoking reduces the speed of progression.... bronchitis
Symptoms: Influenza-like fever, breathlessness, cough.
Prognosis: Chronic lung damage and progressive disability.
Indicated: antifungals, antibiotics.
Alternatives. Teas. Marigold, Ground Ivy, Scarlet Pimpernel, Yarrow. 1 heaped teaspoon to each cup boiling water; infuse 5-15 minutes; 1 cup freely.
Tablets/capsules. Garlic, Echinacea, Goldenseal, Thuja.
Powders. Combine, parts, Echinacea 3; Goldenseal 1; Thuja 1. Dose: 500mg, (two 00 capsules or one- third teaspoon) thrice daily.
Decoction. Irish Moss, to promote expectoration and eliminate debris.
Tinctures. Alternatives. (1) Echinacea 2; Lobelia 1; Liquorice 1. (2) Equal parts: Wild Indigo, Thuja and Pleurisy root. (3) Echinacea 2; Marigold 1; Thuja half; Liquorice half. Dosage: two 5ml teaspoons in water thrice daily. Acute cases: every 2 hours.
Topical. Inhalation of Eucalyptus or Tea Tree oils.
Diet. See: DIET – GENERAL. Yoghurt in place of milk.
Note: Bronchodilators of little value. Those at risk should have an X-ray at regular intervals. ... farmer’s lung
Because they are not bronchodilator drugs, and will not relieve an existing attack, they are usually used with bronchodilators and inhaled corticosteroids to reduce the frequency of attacks.
Side effects include gastrointestinal disturbances and headache.
Skin and hypersensitivity reactions may also occur.... leukotriene receptor antagonists
Habitat: Kashmir, Himachal Pradesh and Garhwal at 25003,000 m; cultivated in Kashmir and neighbouring regions.
English: Kuth, Costus.Ayurvedic: Kushtha, Kusht, Vaapya, Kaashmira, Gada, Rug, Ruk, Aamaya, Paalaka. (Substitute: Pushkara Muula, Inula racemosa.)Unani: Qust.Siddha/Tamil: Kostum, Kottam.Folk: Sugandha-Kuutth.Action: Root—antispasmodic, expectorant, carminative, astringent, antiseptic. An ingredient of prescriptions for dyspepsia, asthma, cough, chronic rheumatism, skin diseases. Applied locally to wounds and ulcerations. Powdered root, mixed with mustard oil, is applied to scalp in prurigo.
The Ayurvedic Pharmacopoeia of India recommends the root in cough, bronchitis, dyspnoea; erysipelas and gout.The root (containing both the essential oil and alkaloid, saussurine) is used for asthma, particularly of vagotonic type. It produces a definite relaxtion of the bronchioles. The relief obtained is comparable to that of conventional bronchodilators without side effects, like a rise in blood pressure, sweating or headache even on repeated administration.Saussurine depresses parasympa- thetic nervous system. The aminoacid- sesquiterpene adducts, saussureami- nes A, B and C show antiulcer effect. The aqueous extract of the root exhibits antianginal activity.Essential oil inhibits peristalic movement of the gut. It is absorbed from the gastro-intestinal tract and partly excreted by lungs producing an expectorant action and partly by the kidneys producing diuretic effect. (In Western herbal, Kuth essential oil is not prescribed internally.)Kuth roots contain resinoids (6%), and essential oil (1.5%), alkaloid (0.05%) inulin (18%), saussurea lactone (20-25%), a fixed oil and minor constituents like tannin and sugars. Roots obtained from Kashmir are, in general, richer in essential oil content than roots obtained from Garhwal and Nepal. The roots of Punjab variety gave cos- tunolide, dehydrocostuslactone, costic acid, palmitic and linoleic acids, beta- sitosterol and alpha-cyclocostunolide. The Kashmir variety, in addition, gave alantolactone, beta-cyclocostunolide and iso-alantolactone.The essential oil of the roots exhibit strong antiseptic and disinfectant activity against Streptococcus and Staphy- lococcus.Costus speciosus Sm. synonym Banksea speciosa, also known as Kush- tha, is a different herb of Zingiberaceae family. Rhizomes and stems yield dios- genin.Dosage: Root—0.2-1.0 g powder. (API, Vol. I.)... saussurea lappa
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