Whilst meningitis is considered a rare disease, there are even rarer forms that can still be as harmful as the ones previously mentioned on this page. They include:
- Parasitic meningitis
- Non-infectious meningitis
- Chemical meningitis
- Malignant or carcinomatous meningitis
- Other non-infectious causes of meningitis
Listeria meningitis is very rare mainly due to effective education campaigns on it. The bacteria can be found in foods like unpasteurised milk, soft cheeses, pate, shellfish, and unwashed vegetables.
The bacteria may cause flu-like symptoms with diarrhoea in pregnant women and perhaps premature labour.
Certain parasites can cause meningitis including Amoebic meningitis – Naegleria Fowleri. These bacteria live in warm fresh water lakes or ponds and poorly maintained swimming pools. People can become infected when people swim or dive into this affected stagnant water. The water enters through the nose and then moves to the brain, where it can cause meningitis.
Certain drugs may cause chemical meningitis including contrast agents used in x-rays or scans and some medicines used to treat cancers.
Fat droplets leaking into the space between the skull and brain due to rupture of benign tumours can also cause chemical meningitis.
Chemical meningitis does not contain bacteria or organisms in the cerebrospinal fluid.
Chemical meningitis may resolve itself with treatment, or may require steroid therapy to limit inflammation and or surgery to remove a tumour.
Malignant meningitis is a disease caused by cancer. This type of meningitis is quite rare and affects less than 5% of cancer patients with a solid tumour such as breast cancer and lung cancer.