Rhinitis medicamentosa
Rhinitis medicamentosa is a form of drug-induced nonallergic rhinitis which is associated with nasal congestion brought on by the use of certain oral medications (primarily sympathomimetic amine and 2-imidazoline derivatives) and topical decongestants (e.g., oxymetazoline, phenylephrine, xylometazoline, and naphazoline nasal sprays) that constrict the blood vessels in the lining of the nose. Chronic atrophic rhinitis
Chronic rhinitis is a form of atrophy of the mucous membrane and glands of the nose. Rhinitis sicca
Chronic form of dryness of the mucous membranes. Polypous rhinitis
Chronic rhinitis associated with polyps in the nasal cavity. Pathophysiology
Most prominent pathological changes observed are nasal airway epithelial metaplasia in which goblet cells replace ciliated columnar epithelial cells in the nasal mucous membrane. This results in mucin hypersecretion by goblet cells and decreased mucociliary activity. Nasal secretion are not adequately cleared with clinical manifestation of nasal congestion, sinus pressure, post-nasal dripping, and headache. Over-expression of transient receptor potential (TRP) ion channels, such as TRPA1 and TRPV1, may be involved in the pathogenesis of non-allergic rhinitis. Association between rhinitis and asthma
Neurogenic inflammation produced by neuropeptides released from sensory nerve endings to the airways is a proposed common mechanism of association between both allergic and non-allergic rhinitis with asthma. This may explain higher association of rhinitis with asthma developing later in life. Environmental irritants acts as modulators of airway inflammation in these contiguous airways. Development of occupational asthma is often preceded by occupational rhinitis. Among the causative agents are flours, enzymes used in processing food, latex, isocyanates, welding fumes, epoxy resins, and formaldehyde.
Toxic leukoencephalopathy is a rare condition that is characterized by progressive damage (-pathy) to white matter (-leuko-) in the brain (-encephalo-), particularly myelin, due to causes such as exposure to substance use, environmental toxins, or chemotherapeutic drugs. The prevalence of this disease is infrequent and often goes unreported, especially in cases resulting from substance use. Magnetic resonance imaging (MRI) is a popular method to study and diagnose the disease. However, even with technological advances, the exact mechanism and underlying pathophysiology of toxic leukoencephalopathy remains unknown and is thought to vary between sources of toxicity. The clinical severity of toxic leukoencephalopathy also varies among patients, exposure time, concentration, and purity of the toxic agent. Some reversibility of the condition has been seen in many cases when the toxic agent is removed. Signs and symptoms
Symptoms vary widely between sources of toxicity, dosage, length of time patient was exposed to the toxic substance, patient history, and patient genetics. Especially in the case of leukoencephalopathy developing due to substance use or environmental toxins, symptoms typically do not develop until several days to months after exposure to the pharmacological agent. Clinical features range from inattention, forgetfulness, and changes in personality to dementia, coma, and even death. Obvious signs of the condition are difficulty with cognitive function and equilibrioception. Common initial symptoms include confusion, somnolence, generalized seizures, headaches, and vision impairment.Young acute lymphoblastic leukemia patients with methotrexate-induced leukoencephalopathy appear asymptomatic. However, toxic leukoencephalopathy induced by substance use or environmental toxins have had more damaging side effects.