General Considerations

Familial susceptibility, environmental exposure, and such modifying factors as psychogenic stimuli must all be considered in the etiologic evaluation of an allergic patient. Half of these patients give a definite history of family allergy (rhinitis, asthma, eczema, urticaria). Seventy-five per cent of children with 2 allergic parents will be allergic. A familial history gives no information, however, about the specific clinical expression of the allergy.

Most allergic disorders of the respiratory tract are caused by inhalant allergens, principally pollens (especially the ragweed family), animal danders, and housedusts.

Modifying factors (psychic stress infections, endocrine distur­bances) may precipitate symptoms by upsetting the "balance" between the patient and his allergenic environment. The antigen-antibody reaction then results, and leads to the rapid appearance of reversible tissue changes; increased capillary permeability, in­creased secretion of mucus, spasm of smooth muscle, and increased

numbers of eosinophils in the tissues, secretions and peripheral blood.

The onset of bronchial asthma is usually before 20 years of age.

Clinical Findings

A. Symptoms and signs:Bronchial asthma is characterized by
recurrent acute attacks of wheezing, dyspnea, cough, and expec­
toration of mucoid sputum (especially at the end of an attack).
Coughing at night, coughing and wheezing on exertion, and a
history of frequent "colds" may be more prominent in children
than clear-cut paroxysms of wheezing. Nasal symptoms (itching,
congestion, and watery discharge) may precede attacks of wheezing.

The acute attack presents a characteristic picture. The patient sits up, "fighting for air", with his chest fixed in the inspiratory position and using his accessory muscles of respiration. Great difficulty is evident with expiration. Wheezing may be audible across the room and usually overshadows other pulmonary signs.

When bronchial asthma becomes prolonged, with acute, severe, intractable symptoms, it is known as status asthmaticus.

B. Laboratory findings:The sputum is characteristically tena­
cious and mucoid, containing "plugs" and "spirals". Eosinophils are
seen microscopically.

C. X-ray findings:Chest films usually show no abnormalities.
Emphysema may be acute (reversible) in severe paroxysms or
chronic (irreversible) in long-standing cases. Transient, migratory
pulmonary infiltrations have been reported. Pneumothorax may
complicate severe attacks.

Complications.Chronic bronchial asthma may lead to such complications as chronic pulmonary emphysema and chronic cor pulmonale. Other complications are atelectasis, pulmonary infection and pneumothorax.

Treatment.The treatment during attacks consists mainly of the administration of substances that alleviate or arrest the paroxysm. Such old substances as adrenaline and ephedrine have not lost their efficiency and are still prescribed in severe and prolonged paroxysms.

Besides those in some subacute cases when typical expiratory dyspnea, cyanosis restlessness and tachycardia are observed the preparations of theophedrine, antasthmane, euphylline, novodrine, neoepinephrine* and others are administered. In severe cases hormonotherapy (ACTH, cortisone, prednisolone) is indicated.

neoepinephrine — изадрин

To support the cardiac activity strophanthin or isolanid (a digitalis preparation) as well as oxygen therapy should be prescribed.

To dissolve mucoid expectorations aerosolic inhalations and bronchial lavage should be provided.

Change in environic conditions is very desirable for the asthmatic patients, climatic therapy (altitute and sea sanatoriums, altitude chambers* and salt mines**) being the most beneficial.

However, before any treatment is administered all possible alimentary allergens and those of environments must be elicited and removed.

The attack often subsides without treatment, sudden death during paroxysms is rare. Proper hygienic measures, relief of apprehension by reassurance, fresh air and rest are the most reliable agents for checking asthma. The institution of such a regimen for prolonged periods causes the attacks to subside.

Sometimes relief is obtained by the. surgical removal of enlarged tonsils and adenoids, and also by nose therapy (rhinitis), as these are also frequent factors in the origin of respiratory disorders.

Prognosis.Most patients with bronchial asthma adjust, well to the necessity for continued medical treatment throughout life. Inadequate control or persistent aggravation by unmodifiable envi­ronmental conditions favors the development of incapacitating or even life-threatening complications.

Date: 2016-04-22; view: 844