Congenital malformations, deformities, and chromosomal abnormalities (Q00-Q99).
- CHARGE syndrome (“coloboma, heart defect, atresia choanae, retarded growth and development, genital abnormality, ear abnormality”) – genetic disorder with autosomal dominant inheritance; characteristics include coloboma (cleft formation), vitium (heart defect), choanal atresia (occlusion of the posterior nasal opening), growth and developmental retardation, genital abnormalities, ear malformations
- Neuroectodermal syndrome type Johnson (synonyms: Alopecia-anosmia-deafness-hypogonadism syndrome, Johnson-Mcmillin syndrome) – genetic disease with autosomal dominant inheritance; characterized by combination of alopecia (hair loss), olfactory dysfunction, conductive hearing loss, malformation of the ears and hypogonadism (hypogonadism).
Respiratory System (J00-J99)
- Allergic rhinitis (AR; hay fever) – olfactory disturbances are considered a leading symptom in this disease (incidence 20-40%).
- Septum deviation (nasal septum curvature).
- Polyposis nasi – occurrence of multiple nasal polyps (mechanical displacement of the scent stream to the regio olfactoria).
- Sinunasal-related olfactory disorders (olfactory disorders occur insidiously over months and years):
- Chronic sinusitis (sinusitis).
- Chronic recurrent rhinosinusitis (RS; simultaneous inflammation of the nasal mucosa (“rhinitis”) and the mucosa of the paranasal sinuses).
- Rhinosinusitis – simultaneous inflammation of the nasal mucosa (“rhinitis”) and sinuses (“sinusitis“).
Endocrine, nutritional and metabolic diseases (E00-E90).
- Diabetes mellitus (diabetes) – patients 60 years of age and older treated with both insulin and oral antidiabetic drugs were three times more likely to exhibit phantosmia (perception of odors in the absence of a stimulus source) than nondiabetics or diabetics treated with insulin alone
- Hypercholesterolemia – treated patients with hypercholesterolemia were twice as likely to report phantosmia as those with cholesterol levels in the normal range
- Kallmann syndrome (synonym: olfactogenital syndrome) – genetic disorder that can occur sporadically and be inherited in an autosomal dominant, autosomal recessive, and X-linked recessive manner; symptom complex of hypo- or Anosmia (decreased to absent sense of smell) in conjunction with testicular or ovarian hypoplasia (defective development of the testis or ovaries, respectively); prevalence (disease frequency) in males 1: 10,000 and in females 1: 50,000.
Infectious and parasitic diseases (A00-B99).
- Viral infections → postviral olfactory dysfunction: more common in women than in men; >50 years of age; improvement in about 60% of those affected; occurrence, for example, in:
- Influenza
- SARS-CoV-2 (synonyms: novel coronavirus (2019-nCoV); 2019-nCoV (2019-novel coronavirus; coronavirus 2019-nCoV); Wuhan coronavirus): approximately 30% of patients testing positive with mild symptoms reported hypo- to anosmia as one of their major symptoms.
Circulatory system (I00-I99)
- Apoplexy (stroke) – patients with apoplexy are 76 percent more likely to have phantosmia
- Hypertension (high blood pressure) – hypertensive patients are more likely to have phantosmia
Musculoskeletal system and connective tissue (M00-M99).
- Osteodystrophia deformans (Paget’s disease) – disease of the skeletal system in which there is a gradual thickening of the bones, especially the spine, pelvis, extremities and skull.
Neoplasms – tumor diseases (C00-D48).
- Neoplasms in the area of the brain
Psyche – nervous system (F00-F99; G00-G99)
- Depression
- Familial dysautonomia (Riley-Day syndrome) – genetic disorder inherited in an autosomal recessive manner; affects almost exclusively Ashkenazi Jews; the disorder results in autonomic nervous system dysfunction.
- Alzheimer’s disease
- Parkinson’s disease (shaking palsy) – hyposmia (reduction in olfactory perception) precedes diagnosis by up to 10 years
- Multiple sclerosis (MS)
- Progressive paralysis – manifestation of neurosyphilis, which proceeds as psychosis with neurological deficits.
- Psychosis
Symptoms and abnormal clinical and laboratory findings not elsewhere classified (R00-R99)
- Respiratory dysosmia – olfactory disturbances due to obstructed nasal breathing.
Injuries, poisonings and other consequences of external causes (S00-T98).
- Allergy, unspecified
- Commotio cerebri (concussion of the brain)
- Contusio cerebri (brain contusion)
- Formaldehyde poisoning
- Carbon monoxide poisoning
- Fractures (broken bones) of the skull
- Traumatic brain injury (TBI)
Further
- Biographical causes
- Age: Physiological dysosmia (olfactory dysfunction) occurs with increasing age; after the age of 50, approximately one quarter of the population have deteriorated olfactory ability (presbyosmia)
- Consumption of stimulants
- Tobacco (smoking)
- Drug use
- Amphetamines
- Cocaine
- Radiatio (radiotherapy)
- Chemotherapy
Medication
- Medication side effects such as:
- ACE inhibitors
- Amphetamines
- Antidepressants such as amytriptyline
- Antihypertensives such as diltiazem (calcium antagonist), nifedipine (calcium antagonist).
- Anticoagulants (phenprocoumon).
- Aminoglycosides
- Persistent use of nasal spray
- Interferon
- L-Dopa
- Penicillamine
- Thiamazole
- Cytostatic drugs such as cisplatin, methotrexate
Environmental pollution – intoxications (poisoning).
- Chemical/toxic agents, unspecified (e.g., e.g., gases, metals, solvents; pesticides).
- Formaldehyde poisoning
- Carbon monoxide poisoning