Intrinsic asthma

Intrinsic asthma, also called idiopathic asthma, usually develops in adulthood. In intrinsic asthma allergic factors are not demonstrable. Episodes of intrinsic asthma may be triggered by a variety of stimuli, eg, emotional state, exposure to cold air, or inert dusts. Both intrinsic and extrinsic asthmatics can be prone to exercise-induced attacks. Individuals who experience a combination of extrinsic and intrinsic asthmatic reactions have mixed asthma. Status asthmaticus refers to an especially acute life-threatening asthma attack which is resistant to normal treatments and which may require hospitalization in order to stabilize the patient. 

Intrinsic asthma (also called nonallergic asthma and caused by chronic or recurrent respiratory infections, emotional upset, and exercise)... 

Mixed asthma (caused by both intrinsic and extrinsic factors)... 

The answer is d. (Katzung, pp 336-3373 The inhibitory effect of mediator release of cromolyn is cell specific In mast cells exposed to cromolyn, inhibition of the early response occurs to antigen challenge, while in eosinophils, it affects the late response, and in basophils it has almost no effect on mediator release. Cromolyn is effective in anti gen-induced asthma, occupation-exposure asthma, and in some cases of intrinsic asthma. Administration of cromolyn by inhalation is most effective in treating patients. 

According to current thinking, epithelial dysfunction, either intrinsic to asthma or caused by persistent inflammation, leads to epithelial release of profibrotic cytokines such as epidermal growth factor and TGF-P acting on fibroblasts and smooth muscle cells, disturbing the equilibrium... 

During the acute phase of thyrotoxicosis, B-adrenoceptor blocking agents without intrinsic sympathomimetic activity are extremely helpful. Propranolol, 20-40 mg orally every 6 hours, will control tachycardia, hypertension, and atrial fibrillation. Propranolol is gradually withdrawn as serum thyroxine levels return to normal. Diltiazem, 90-120 mg three or four times daily, can be used to control tachycardia in patients in whom blockers are contraindicated, eg, those with asthma. Other calcium channel blockers may not be as effective as diltiazem. Adequate nutrition and vitamin supplements are essential. Barbiturates accelerate T4 breakdown (by hepatic enzyme induction) and may be helpful both as sedatives and to lower T4... 

Calcium channel blockers have an intrinsic natriuretic effect therefore, they do not usually require the addition of a diuretic. These agents are useful in the treatment of hypertensive patients who also have asthma, diabetes, angina, and/or peripheral vascular disease. 

Capsaicin causes transient bronchoconstriction and induces coughing, especially in individual with severe asthma, potentially triggering fatal crises [37]. These adverse respiratory effects are probably due to the limited capacity of respiratory tissues to metabolize capsaicin (see Section 4.3) [38], and are a major problem with the use of pepper sprays as antiriot agents [37]. Smokers are less sensitive to the respiratory effects of capsaicin, but asthmatic patients should avoid chilies and hot cuisine, as should people using drugs such as ACE-inhibitors, which have an intrinsic capacity to induce cough. 

Some patients exhibit wheeze and breathlessness in the absence of an obvious allergen or atopy. They are considered to have intrinsic asthma and because of a lack of an identifiable allergen, allergen avoidance has no place in their management. 

Acute asthma is a reactive airway disease (RAD) occurring when extrinsic (environmental) or intrinsic (internal) allergens stimulate bronchoconstriction, causing bronchospasms that result in wheezing and difficulty breathing. 

Since tuberculosis, bronchiectasis, emphysema, fibrocystic disease, intrinsic asthma, and hilar sarcoidosis are often associated with a dominant elevation of IgA (see Fig. 10 2), this has no specific value. Pneumocystis pneumonia in infants can elevate IgM (K7) (Fig. 10 6). Of course recurrent respiratory infection is a common mode of presentation of frank immune deficiencies (H32), and we find these in some 4% of patients with such histories. Reaginic states have already been considered under IgE globulin, and immunoglobulin deficiencies among atopic children support the hypothesis that atopic subjects may have a poor immunological dictionary (K2). Direct IgE assay of fluid from nasal polyps can also point to an allergic origin (D6). Parotid saliva normally contains only detectable IgA (see Table 1) (mixed saliva... 

Sibbald B, Turner-Warwick M Factors influencing the prevalence of asthma among first degree relatives of extrinsic and intrinsic asthmatics. Thorax 1979 34 332-337. (Ill)... 

Unfortunately, most diseases of economical and societal interest (e.g., heart disease, cancer, diabetes and asthma) are considered to be such complex diseases, that is, they cannot be attributed to single genes. In this context, the related genes are referred to as susceptibility genes. Such genes may or may not be related functionally they may be unrelated but belong to intrinsic biochemical pathways [8],... 

It is generally thought that these four canonical mechanisms of IgE-mediated activation of human FceRI + cells are responsible for the pathophysiological involvement of these cells in the majority of patients with allergic disorders [34], However, there is evidence that a significant percentage of allergic diseases (e.g. certain cases of intrinsic asthma and chronic idiopathic urticaria) cannot be explained by the four classical mechanisms of FceRI + cell activation. 

Humbert M, Menz G, Ying S, Corrigan CJ, Robinson DS, Durham SR, Kay AB The immunopathology of extrinsic (atopic) and intrinsic (non-atopic) asthma more similarities than differences. Immunol Today 1999 20 528-533. 

Exercise-Induced Asthma. In some asthmatics (usually young, allergic patients) moderate to severe exercise can initiate an asthmatic attack. As with intrinsic asthma, the etiology of exercise-induced asthma has not been well defined. One theory (Deal et al, 1979) suggests that cold-sensitive irritant receptors in the epithelia are associated with afierent nerve fibers within an autonomic reflex arc. Efferent motor fibers of this reflex then return to the airway smooth muscle via the vagus nerve. Thus, bronchoconstriction is induced through this reflex arc by stimulation of the cold-sensitive irritant receptors. 

Celiprolol is a potent beta -adrenergic receptor antagonist. It has intrinsic sympathomimetic action, possesses some alpha2-adrenoreceptor antagonistic properties, is a direct vasodilator, and a direct bronchodilator. Celiprolol is incompletely and variably absorbed, eliminated both in bile and urine, and has a half-life of 4 to 5 hours. Celiprolol (200 to 400 mg/day) has efficacy similar to atenolol or propranolol in reducing blood pressure and is useful in hypertensive patients with asthma or bronchitis. Furthermore, celiprolol is as effective as atenolol in treating patients with stable angina. 

In the treatment of hypertension, a major use of beta-blockers is in combination with hydralazine. The direct vasodilators bring about reflex cardiac stimulation, and beta-blockers prevent these adverse effects (see also Figure 67). Beta-blockers also reduce blood pressure by exerting a central effect or a peripheral action, or both, which decreases renin activity. Metoprolol and atenolol are beta selective, and they are safer agents in patients with asthma, diabetes mellitus, or low-renin hypertension. Some beta-blocking agents such as pindolol have intrinsic sympathomimetic activity and may be used in the treatment of pronounced bradycardia (sick sinus syndrome). Unlike propranolol, metoprolol is not a very lipid-soluble... 

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