Allergic professional diseases of the airways and lungs

It belongs to the category of professional allergic diseases allergic rhinitis and bronchial asthma.

Professional allergic rhinitis

 * It is defined as inflammatory disease nasal mucous membranes, which arises in response to air allergen occurring in the workplace. An estimated 15 – 20% of the population suffers from allergic rhinitis, the proportion of professional rhinitis cannot be estimated.
 * Allergens are either common substances, which in the workplace are to an increased extent ( flour in bakeries, cereal money ... ), or are allergens specific to the work environment ( acid anhydrides in plastics formation ... ). In general, these are the attractions either high molecular weight ( proteins, cereal dusts, insect antigens, latex ... ), or low molecular weight ( diisocyanates, anhydrides, rosin substances, ATB ... ).

Professional exposure
Similar to u asthma: flour processing ( bakers, millers ), grain handling ( farmers ), animal care, contact with disinfection ( paramedics ), woodworking.

Repeated contact with the allergen leads to IgE dependent activation mast cells → vasodilation, edema, nasal obstruction.

 * Mediators inflammation stimulate afferent nerve endings → itchy nose, sneezing.
 * The accumulation of inflammatory cells is characteristic.

Pathology
Edematous mucosa with profuse serous exudation, chronic form has a hyperplastic or atrophic character.

Acute

 * Itching and irritation in the nose, sneezing and watery secretion, often along with itching in the throat, eyes and ears. Asthma is often added to the symptoms.
 * It's about reaction I.type → symptoms occur within minutes, they leave quickly.

Chronic

 * In unknown and untreated recurrent acute rhinitis, they may progress to chronicity after months to years.
 * Dominates feeling of a stuffy nose and dense mucus, there may be chronic conjunctival changes, tearing. Sneezing and itching are usually lacking.

Investigation methods

 * ENT examination,
 * skin intradermal tests – basic range of inhalation allergens ( domestic dust, feathers, mites ... ),
 * increase IgE in serum,
 * Detection of professional specific IgE antigens,
 * nasal mucosal swabs – cytological analysis (predominance of eosinophils),
 * rhinomanometry – measures the resistance of nasal passages by quantitative measurement of nasal flow and pressure,
 * active anterior rhinomanometry is usually used,
 * is also used to assess the response to provocation tests,
 * positive rhinoprovocation test – after contact with the allergen, the nasal flow decreases by at least 40% and the nasal resistance increases by 60 %.
 * Professional assessment – must demonstrate inhalation exposure to an allergic substance in the workplace.
 * decides the clinical picture and the specific immunological response,
 * people often neglect this disease and go to the doctor after a long time.

Differential diagnosis

 * In particular, rhinitis of other origins ( allergic seasonal, year-round ... ), other pathologies in the nasal cavity must also be considered.

Professional bronchial asthma

 * Asthma-induced disease inhalation of harmful nox at work,
 * from the classic asthma is no different,
 * estimate of the proportion of professionalism in asthma – 2 – 15%, the figure is probably significantly underestimated, doctors often do not think about professionalism at all.
 * Factors:
 * high molecular weight ( animal and vegetable proteins ),
 * low molecular weight ( isocyanates, anhydrides, platinum salts ),
 * inhalation chemicals ( chlorine, ammonia ),
 * pharmacologically active substances (insecticides),
 * physical factors (cold).

Professional exposure

 * The most common allergens:
 * flour ( amylase ) – millers, bakers, confectioners,
 * grain dust – workers, farmers,
 * urine and fur laboratory and livestock – research laboratory staff, farmers, breeders,
 * disinfectants – paramedics,
 * natural and synthetic fibers – textile industry,
 * wood dust – sawmills, furniture industry,
 * proteolytic enzymes – food industry, production of washing powders,
 * rosin and other welding fumes – fine mechanics, welding,
 * isocyanates, acrylic resins, color pigments – chemical production.

Ethiopogenesis

 * Chronic inflammatory disease, main cells involved – mast cells and eosinophils,
 * inflammation increases the reactivity of the bronchi, it develops bronchospasm ( obstruction ),
 * mild asthma – is not present between obstruction attacks, but is hyperreactivity,
 * severe asthma – obstruction present even between seizures.

Types of professional asthma

 * Immunological professional asthmaarises in a small number of exposed,
 * after the initial asymptomatic period, by inhaling substances that the worker previously well tolerated,
 * arises specific immunological response on the substance,
 * are caused by two types of substances, depending on which it is a different course,
 * high molecular weight substances – induce an IgE response, gets on quickly,
 * low molecular weight substances – unknown mechanism ( probably type III response. or IV. ), arrival later ( often after returning from work ), it does not subside until 24 hours.


 * Irritation-induced asthma: The mechanism of origin is not entirely clear ( plays a role release neurotransmitters). It is created after exposure to irritants ( dust, aerosol, fumes, smoke ).


 * RADS ( reactive airways dysfunction syndrome ): It is caused by short-term intensive exposure


 * Reflective bronchoconstriction: Non-immunoassay ( without inflammation ), when stimulating neuroreceptors with cold, dust, aerosols, smoke.


 * Pharmacological bronchoconstriction: It is caused by inhalation of substances causing pharmacologically bronchoconstriction, e.g. organophosphates.

Pathology
It is created wall remodeling – thickening of the wall of bronchioles ( muscle hypertrophy ), epithelium high, very cup cells, sometimes even tile metaplasia, occurs hyperplasia goblet cells.

Clinical picture

 * Feeling shortness of breath, whistles with a maximum in the expirium ( often audible at a distance – distance phenomena ).
 * Cough occur only in the workplace or in connection with work ( after work ).
 * Often eye complications, rhinitis…
 * Symptoms get better on weekends and holidays.

Investigation methods

 * Spirometry – obstructive ventilation failure,
 * non-specific bronchoprovoic test – acetylcholine or histamine,
 * we find it non-specifically that the bronchi are hyperreactive.
 * Positive criteria
 * decline FEV1 by 20%, MEF 25 – 75 by 30%, increase in resistance by 100 %,
 * Specific inhalation bronchoprove tests – we administer a specific substance that we suspect, either we administer commercially manufactured products or we do workplace conditions ( in the exposure cabin ),
 * the conditions of positivity are as in a non-specific test,
 * is potentially more dangerous ( we give an allergen, not the body's own substance ... ),
 * only for people who do not have obstruction in peace and for hospitalization.
 * Elimination test – health assessment after long-term exclusion from exposure.
 * Reexposure test – after the previous one, we re-engage in the process and determine the health condition.
 * Skin tests, ID card spec. IgE, BAL…

Differential diagnosis
It is necessary rule out other causes of obstruction – tumors, foreign bodies, laryngeal nerve paresis ... The basic problem is the differentiation of professional asthma and pre-existing asthma exacerbated by work.

Treatment
Exclusion from the exposure, corticoids, β-2-mimetics, anticholinergics, theophylline, antiallergic.

Resources

 * BENEŠ, Jiří. Study materials [ online ]. [ cit. 24.02.2010 ].

Literature used

 * PELCL, Daniela. Occupational diseases and intoxication. 2nd edition. Prague: Karolinum, 2006. 207 p. ISBN 80-246-1183-X.
 * PELCL, Daniela. Occupational diseases and intoxication. 2nd edition. Prague: Karolinum, 2006. 207 p. ISBN 80-246-1183-X.