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|Classification and external resources|
Nasal polyps are polypoidal masses arising mainly from the mucous membranes of the nose and paranasal sinuses. They are overgrowths of the mucosa that frequently accompany allergic rhinitis. They are freely movable and nontender.
Nasal polyps are usually classified into antrochoanal polyps and ethmoidal polyps. Antrochoanal polyps arise from the maxillary sinuses and are the much less common, ethmoidal polyps arise from the ethmoidal sinuses. Antrochoanal polyps are usually single and unilateral whereas ethmoidal polyps are multiple and bilateral.
Symptoms of polyps include nasal congestion, sinusitis, anosmia (loss of smell), and secondary infection leading to headache. They may be removed by surgery, but are found to recur in about 70% of cases. Sinus surgery requires a great amount of precision as this involves risk of damage to orbit matter.
The tendency to manifest multiple polyps is referred to as “polyposis”.
There are 2 major types of nasal polyps.
Nasal polyps consist of hyperplastic oedematous connective tissue with some seromucous glands and inflammatory cells (mostly neutrophils and eosinophils) with respiratory epithelium, sometimes with metaplastic squamous epithelium on the surface.
The pathogenesis of nasal polyps is unknown. Nasal polyps are most commonly thought to be caused by allergy and rarely by cystic fibrosis although a significant number are associated with non-allergic adult asthma or no respiratory or allergic trigger that can be demonstrated. Nasal mucosa, particularly in the region of middle meatus becomes oedematous due to collection of extracellular fluid causing polypoidal change. Polyps which are sessile in the beginning become pedunculated due to gravity and excessive sneezing.
In early stages, surface of nasal polyp is covered by ciliated columnar epithelium, but later it undergoes metaplastic change to squamous type on atmospheric irritation. Submucosa shows large intercellular spaces filled with serous fluid.
These polyps have no relationship with colonic or uterine polyps. Irregular unilateral polyps particularly associated with pain or bleeding will require urgent investigation as they may represent an intranasal tumor.
There are various diseases associated with polyp formation:
- Chronic rhinosinusitis
- Aspirin-induced asthma, or aspirin-exacerbated respiratory disease (AERD)
- Cystic fibrosis
- Kartagener's syndrome
- Young's syndrome
- Churg-Strauss syndrome
- Nasal mastocytosis
Exposure to some forms of chromium can cause nasal polyps and associated diseases.
Chronic rhinosinusitis is a common chronic medical condition that can be classified into two groups presenting either with nasal polyposis or without. Chronic rhinosinusitis with nasal polyposis can be divided into eosinophilic chronic rhinosinusitis, which include allergic fungal rhinosinusitis and aspirin-exacerbated respiratory disease, or nasal polyps associated with neutrophilic inflammation, which is primarily characterized by cystic fibrosis.
Nasal polyps are most often treated with steroids or topical, but can also be treated with surgical methods.
Pre-post surgery, sinus rinses with warm water (240 ml / 8 oz) mixed with a small amount (teaspoon) of salts (sodium chloride & sodium bicarbonate) can be very helpful to clear the sinuses. This method can also be used as a preventative measure to discourage the polyps from growing back and should be used in combination with a nasal steroid.
The removal of nasal polyps via surgery lasts approximately 45 minutes to 1 hour. The surgery can be done under general or local anaesthesia, and the polyps are removed using endoscopic surgery. Recovery from this type of surgery is anywhere from 1 to 3 weeks.
- eMedicine - Nasal Polyps : Article by John E McClay, MD
- Chaaban, Mohamad; Walsh, Erika M.; Woodworth, Bradford A. (Nov–Dec 2013). "Epidemiology and differential diagnosis of nasal polyps". American Journal of Rhinology and Allergy 27 (6): 473–478. doi:10.2500/ajra.2013.27.3981. PMC 3899526. PMID 24274222.
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