Nasal polyps (NPs) are soft, painless, noncancerous jelly-like overgrowths on the lining of your nasal passages or sinuses.
They hang like grapes on the end of a stalk inside your nose. They occur in around 1 in 200 people, mostly by the age of 40 years.
Symptoms of nasal polyps
Most often linked to allergies or asthma, NPs do not always cause symptoms but as they grow down from the sinuses into the nasal cavity, the result is often a blocked nose, microbial build-up and chronic infection. NPs are present in Chronic Sinusitis with Nasal Polyps (CRSwNP)
Larger ones can block normal drainage from the sinuses. NPs can block the tunnels connecting the nose to the sinus cavities preventing circulation of air and mucous. When quite big they may cause a feeling of pressure inside the nose, nasal discomfort and difficulty breathing through the nostrils
Causes of nasal polyps
The cause is unknown, but chronic inflammation in the sinuses from allergy, infection or inflammatory imbalance may trigger NPs and make them grow bigger, faster—and make them regrow after sinus surgery.
An allergic response to fungus may be the main cause of nasal polyps in a few patients who respond to a nasal spray containing an antifungal medication (fungal sinusitis). Unfortunately, it is not easy to determine which NP patients will respond to this treatment and fungal sinusitis is more the exception than the rule.
NPs are seen in 4 situations:
- Chronic sinusitis (CRS with nasal polyps i.e. CRSwNP)
- Cystic fibrosis
- Aspirin sensitivity
NPs occur in:
- 15% of asthma patients
- 25% of cystic fibrosis patients
- Most asthma patients with aspirin sensitivity
- Surgical removal, although they will regrow eventually in most people, especially those with aspirin-induced-asthma.
- Cortisone tablets will shrink them down temporarily, but long-term use is restricted to the most severe cases because of side-effects.
- Cortisone / steroid nose sprays slow polyp growth. People with recurrent polyps who have had multiple operations are often advised to stay on these sprays forever. In people with recurrent disease, nasal steroid sprays should be considered as “weed killers”, which need to be used continuously. Slower growth means fewer sinus infections, less antibiotics and less frequent surgery.
- Allergy desensitization injections are sometimes used in allergic people with hay fever as well as NPs. While this often helps hay fever, it is not known for certain whether the injections help shrink the polyps as well as they decrease the severity of the allergy.
- Diet – there is no evidence that altering the diet will help.
- Other medications – sometimes antifungal sprays and tablets are effective in resistant cases.
- People with aspirin allergy, NPs and asthma (a condition known as the aspirin-induced-asthma) have the option of aspirin desensitization, which can reduce asthma severity, the rate of polyp regrowth and the severity of sinusitis. The decision to undertake aspirin desensitization should be made by an allergy specialist.
Eosinophilic or Non-Eosinophilic CRS
Although their exact pathogenesis is unclear, NPs are generally characterized by edematous masses of inflamed mucosa and abundant inflammatory cells. The majority of NPs encountered in Western populations suffering from CRSwNP are said to be eosinophilic.
Eosinophiles are a variety of white blood cells and one of the immune system components responsible for combating multicellular parasites and certain infections in vertebrates.
Eosinophilia, i.e. an abnormal increase in eosinophils, is typically seen in people with a parasitic infestation of the intestines; autoimmune and collagen vascular disease (such as rheumatoid arthritis) and Systemic lupus erythematosus; malignant diseases such as eosinophilic leukemia, clonal hypereosinophilia, and Hodgkin’s disease; lymphocyte-variant hypereosinophilia; extensive skin diseases (such as exfoliative dermatitis); Addison’s disease and other causes of low corticosteroid production (corticosteroids suppress blood eosinophil levels); reflux esophagitis (in which eosinophils will be found in the squamous epithelium of the esophagus) and eosinophilic esophagitis; and with the use of certain drugs such as penicillin. But, perhaps the most common cause for eosinophilia is an allergic condition such as asthma.
It is noteworthy to add that non-eosinophilic NPs feature in a significant percentage of CRSwNPs reported in Asian countries.