Cromolyn sodium and nedocromil sodium are inhaled agents that are alternatives to inhaled corticosteroids (ICS) in the management of mild persistent asthma in children. Both drugs have been shown to possess anti inflammatory properties through nonsteroidal mechanisms, although the exact mechanisms for their actions remain unclear. (more…)

Treg cells or regulatory T cells constitute a large population of cellular infiltrate in atopic/allergic inflammation and a dysregulated immune response appears to be an important pathogenetic factor. Cardinal events during allergic inflammation can be classified as activation, organ-selective homing, survival and reactivation, and effector functions of immune system cells. T cells are activated by aeroallergens, food antigens, autoantigens, and bacterial exotoxins superantigens in allergic inflammation. They are under the influence of the skin, lung, or nose-related chemokine network and show organ-selective homing. (more…)

A variety of proinflammatory cells, mediators, and cytokines orchestrate the development of airway hyperresponsiveness, which results in the episodic airflow obstruction characteristic of asthma. As a consequence, modulation of the underlying disease process with antii-nflammatory agents is firmly established as being the cornerstone of successful management. Inhaled corticosteroids are the most potent antiinflammatory agents available and satisfactorily suppress underlying airway inflammation in most individuals. (more…)

The Ras-dependent pathway can be triggered by a variety of cytokine receptors, as well as by certain adhesion molecules and by many other surface receptors when they contact appropriate ligands. Signaling in this pathway can be initiated by cytosolic proteins called Src-family kinases, so named because they bear regions of sequence homology to the oncoprotein Src. These Src-like kinases contain specialized protein domains, termed SH2 domains (for Src-homology region 2), that enable them to bind other proteins containing phosphorylated tyrosine residues. When a cytokine receptor binds ligand, subunits of the receptor become phosphorylated and can immediately be bound by a Src-family kinase. (more…)

Routes by which infectious organisms gain entry into the body include the skin, respiratory tract, gastro-intestinal (GI) tract and GU tract. There are fundamentally two ways in which infectious agents cross the physical and chemical barriers: either they are able to penetrate the intact barriers at one or more anatomical sites, or the physical barriers are damaged and breached, allowing entry of the organism.

Bellow are some possibles pathogens entry into human body:

Penetration of intact skin or mucosa

• Skin. Few organisms are able to penetrate intact skin. However, some parasites (e.g. hookworm) or their larvae (e.g. schistosoma) can do this. Other agents, such as wart viruses, set up infection in the skin and do not enter further into the body.

• Mucosa. Mucosa, being softer and damper than skin, are much more frequent sites of entry and all intact mucosa can be penetrated by some organisms. Examples are shown in table bellow. Pathogens can cross epithelia by passing through epithelial cells, as in the case of the meningococcus (a bacteria causing meningitis), or by passing between the epithelial cells, seen with Haemophilus influenzae.

Mucosal Sites of Entry for Pathogens

Penetration of damaged skin or mucosa

There are many ways in which skin or mucosa can be damaged, allowing entry of infectious organisms that could not cross intact skin or mucosa. Damage to skin is a particularly important route of infection and can occur in a number of ways:

• Burns. Burns, especially severe ones, pose a major risk for infection, particularly with Staphylococcus, Streptococcus, Pseudomonas and Clostridium tetanus.

• Cuts and wounds. These can allow entry of similar organisms to those seen after burns.

• Insect bites. Numerous infections pathogenesis are transmitted via insect bites. These include malaria, typhus and plague.

• Animal bites. Animal bites can provide direct transmission of infection, such as in rabies. Because they cause significant damage to the skin, bites can allow the entry of the same environmental pathogens as burns, cuts and wounds (see above).

• Human behaviour. Various aspects of uniquely human behaviour can result in the skin being penetrated. Sharing of syringes by intravenous (IV) drug users exposes them to risk of hepatitis and human immunodeficiency virus (HIV). A number of viral infections (hepatitis, HIV) have been transmitted by blood transfusion and blood products (e.g. factor VIII for haemophiliacs) before appropriate screening procedures were developed. Transplantation has also resulted in transmission of infection before the introduction of appropriate donor screening.

Damage to mucosa may not increase the likelihood of infection to the same extent as damage to the skin. However, physical or chemical damage may allow entry of some organisms (e.g. smoking increases the risk of respiratory bacterial infections or respiratory allergies). Furthermore, infection of the mucosa with a virus may cause damage and facilitate the entry of bacterial pathogens spread.

Tumour Necrosis Factor is a pro-inflammatory cytokine implicated in the pathogenesis of asthmatic airway inflammation, hyper-reactivity and remodelling. The primary aim of the trial was to assess whether TNF antagonism, using a soluble Tumour Necrosis Factor receptor (TNFR:Fc etanercept, Enbrel ® ), can attenuate eosinophilic airway inflammation in patients with mild to moderate allergic asthma. (more…)

Allergen avoidance has been recommended in the management of allergic asthma children. Very few studies have assessed the effect of pet removal on pet allergic asthma. The authors examined the effect of pet removal from homes on pulmonary function testing, bronchial
hyper-responsiveness and medication use. This was a prospective, controlled but non-randomized and open study. Subjects included 20 symptomatic patients with newly diagnosed pet allergic asthma who were keeping domestic animals, including hamsters, cats, dogs and ferrets, and were sensitized to these animals. (more…)

Diagnosis of food hypersensitivity is a clinical challenge and the only current definitive test is the Double Blind Placebo-Controlled Food Challenges. Although the Double Blind Placebo-Controlled Food Challenges is the current gold standard, it is difficult to perform and is very time-consuming. Hence, researchers are continually evaluating new tests and assessing the value of the available serum tests. (more…)

Asthma and allergic diseases are common in both children and adults. Their development depends on an interaction between asthma genetic and asthma environmental risk factors. Genetic manipulation in multi factorial diseases such as asthma is not feasible in the foreseeable future. However, theoretically, environmental exposures can be controlled in an attempt to stem the rising prevalence of these diseases (primary prevention). Environmental exposures may also influence the frequency of symptoms and the requirement for medication in those with established disease. (more…)

The effects of exposure to environmental tobacco smoke (ETS) on children have been extensively studied and numerous surveys have consistently reported an association between environmental tobacco smoke exposure and respiratory diseases or respiratory allergies. Strong evidence exists that passive smoking increases the risk of lower respiratory tract illnesses such as bronchitis, wheezy bronchitis and pneumonia in infants and young children. (more…)