ASTHMA, ECZEMAMichael Widjaja

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黄合乐

Outline

Preconceived notions How allergic asthma is triggered Mechanism of asthma Methods of treatment of asthma Factors that lead to asthma Eczema and the factors that lead to it Link between asthma and eczema Conclusion

Initial thoughts on asthma

Asthma causes difficulty in breathing Consists of two parts

Constriction of bronchi Overproduction of mucus in respiratory tract

Caused by Allergies Drastic change in temperature Exercise Heritable? family history

Initial thoughts on Eczema

Dry itchy skin, redness, cracking, oozing or bleeding

Causes Allergies Skin Irritants Dry weather Sweat

Eczema linked to Asthma in some way Genetically linked disease?

Anatomy of Asthma

Triggers of Asthma

Dust Pollen Cockroaches Cold air Smoke Animal dander, skin, dried saliva, hair

Mast Cells and Plasma Cells

Mechanism of Asthma

Antigen enters body Plasma cell produce immunoglobulin

E(IgE) IgE binds to surface of mast cells Future exposures to antigen results in

binding of antigen to surface bound IgE Mast Cells degranulate releasing

Histamine and Leukotriene

Mast Cell Degranulation

Steroid effects of the lung

Leukotriene promotes contraction of smooth muscle of the bronchioles

Histamine increases vascular permeability, causing capillary leakage and edema

Treatment of Asthma

Inhaled corticosteroids are preventive medications that treat inflammation of the airways

Bronchodilators (long-acting beta-2 agonist) relax the muscles surrounding the airways for a long period of time

Hereditary factors for Asthma Study done in Arizona involving 344

families

Environmental factors for Asthma

Genes related to Asthma

Multifactorial 25 genes more commonly associated

with asthma Related to immune system or

inflammation Studies are inconsistent

Environmental factors in Asthma Tobacco smoke Air pollutants Caesarean sections Psychological stress – modulates

immune system Hygiene hypothesis

Environmental Factors Reduction of indoor allergens

moderately reduces risk of developing asthma

Conversely exposure to cat and dog allergens during first year of life reduced allergy to cat and dog allergens and developing asthma

Eczema- inflammation of epidermis Redness Crusting Flaking Blistering Cracking Oozing Bleeding Edema

Types of Eczema

Atopic Eczema- due to an overactive immune system

Contact Eczema- contact with allergens Xerotic eczema – results from dry skin

during the winter Seborrhoeic dermatitis- cause cradle cap

in infants

Histology of Eczema

Filaggrin gene encodes protein profilaggrin which forms a protective barrier that keeps moisture in and infectious organisms out

Similar to asthma, allergens can bind to IgE receptors on mast cells causing histamine to be released and edema to occur

Filaggrin gene

Linked: Asthma, Eczema, Hay Fever Location: 1q21.3 Function:

Bundles keratin intermediate filaments Promotes disulfide-bond formation among

theintermediate filaments mammalian epidermis

Treatment of Eczema

Moisturizer to fight dry skin Steroid cream to repress immune

system and reduce swelling

Genetics of Eczema

Similar to asthma related to family history of allergies

Multiple genes factor control our immune system

Also similar to asthma, environmental factors Filaggrin gene SPINK5(Serine protease inhibitor Kazal-type

5) gene plays a role in anti-inflammatory and antimicrobial protection of mucous epithelia

Link between Asthma and Eczema Atopic march

50-70% of children with severe eczema developed Asthma

2/3 of these children will also develop allergic rhinitis

Link between Asthma and Eczema Research done by Washington University

School of Medicine

Experimented on mice Mice were engineered to have defective skin

similar to eczema in humans produced TSLP ( thymic stromal lymphopoietin) and developed asthma

Mice with normal skin but overproduced TSLP also developed asthma

Link between Asthma and Eczema TSLP( thymic stromal lymphopoietin)

TSLP also produced in Asthma patients Secreted into blood stream when skin is damaged,

indicating its protective barrier is damaged and further protections are needed

Both lung and skin in contact with open environment Inflammatory disease of skin also causes

inflammation of lungs when TSLP flows in bloodstream to the lungs

TSLP causes lungs to be very sensitive to allergens

Summary

Mechanism of Asthma Triggers of Asthma Genetic and Environmental factors of

Asthma Cause of Eczema Genetic and Environmental factors of

Eczema Link between Asthma and Eczema

Citations

http://acc6.its.brooklyn.cuny.edu/~scintech/asthma/Genetics2.htm

http://www.mamashealth.com/allergies/breathbet.asp http://en.wikipedia.org/wiki/Asthma http://en.wikipedia.org/wiki/Eczema http://www.blisstree.com/articles/filaggrin-gene-and-

eczema/ http://www.thetech.org/genetics/ask.php?id=161 http://www.blisstree.com/articles/filaggrin-gene-and-

eczema/ http://news.bbc.co.uk/2/hi/health/8055038.stm http://www.news-medical.net/news/2009/05/18/

Researchers-look-at-eczema-asthma-link.aspx

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