The perception of an unpleasant odor seemingly originating from the side of the nose is a common experience. This sensation can be caused by an actual external scent produced by the skin, or it may be a perceived smell arising from deeper internal structures. Pinpointing the exact source is the first step toward finding relief, as causes range from simple hygiene issues to complex infections within the nasal passages. Sometimes, the odor is a phenomenon known as phantosmia, where a person detects a smell that is not physically present, which can indicate neurological changes or chronic inflammation.
Surface and Skin-Related Causes
The side of the nose, particularly the creases where it meets the cheek, is densely populated with sebaceous glands, which produce a natural, oily substance called sebum. Sebum is composed of various lipids, designed to lubricate and protect the skin. When this oil combines with sweat, dead skin cells, and normal skin bacteria, it begins to break down, releasing volatile compounds that can produce a noticeable, sometimes sour or rancid, odor.
This localized smell is often more pronounced in the alar groove, the fold along the nostril, where moisture and debris are easily trapped. Improved hygiene, such as gentle cleansing that targets this area, can often resolve the issue by preventing the buildup of these odor-producing mixtures.
A localized bacterial infection known as nasal vestibulitis can also occur in the hair follicles just inside the nasal opening. This condition is frequently caused by the Staphylococcus aureus bacterium entering through small breaks in the skin from activities like nose picking or excessive hair plucking. Nasal vestibulitis can lead to crusting, tenderness, and pimple-like sores near the rim of the nostril, which may generate a foul smell.
External factors also contribute, such as wearing glasses or a mask, which can trap moisture and increase temperature in the area. This warm, humid environment encourages the growth of skin flora, leading to the accelerated decomposition of sebum and a stronger, more persistent scent.
Odors Originating from Sinus and Nasal Passages
In many cases, an odor perceived near the nose actually originates from inside the nasal cavity or the adjacent sinus structures. The most frequent internal source is a bacterial infection of the sinuses, known as sinusitis, which can be either acute or chronic. When the sinus drainage pathways become blocked, mucus stagnates, creating an ideal environment for anaerobic bacteria to flourish.
These specific bacteria produce foul-smelling gases, often containing sulfur compounds, that result in a distinctive, rotten odor. The infected mucus can then drain into the back of the throat in a process called post-nasal drip, or it can accumulate within the nasal passages, where the smell is readily detected.
Structural issues within the nose can also predispose an individual to this problem by impeding proper drainage. Conditions like a severely deviated nasal septum or the presence of nasal polyps can physically block the flow of mucus. This obstruction allows secretions to pool and become infected, which then leads to the generation of the same malodorous compounds. Addressing the underlying structural or infectious cause is necessary to eliminate the persistent internal odor.
Contributing Factors from Adjacent Areas
Sometimes, the source of the foul smell is not the nose itself but a nearby anatomical region, with the odor traveling into the nasal passages. Significant dental issues, such as untreated tooth decay, gum disease (periodontitis), or a dental abscess, are common contributors. Bacteria in the mouth produce gases that can move up the nasopharynx, the area connecting the back of the nose to the throat, where they are perceived as a nasal odor.
This is distinct from sinusitis because the infection is localized to the oral cavity. A more specific, though rare, nasal condition that causes a severe odor is atrophic rhinitis, also known as Ozena. This chronic disorder involves the progressive thinning and drying of the nasal lining and underlying bone.
Atrophic rhinitis leads to the formation of large, thick, dry crusts inside the nose. These crusts become colonized by certain bacteria, like Klebsiella ozaenae, which release compounds that result in an intensely foul smell. Individuals with this condition may, paradoxically, not perceive the full extent of the odor themselves due to damage to their sense of smell, a phenomenon called merciful anosmia.
Seeking Professional Diagnosis and Treatment
A persistent or worsening odor from the nose warrants a consultation with a healthcare professional, especially if it is accompanied by other symptoms. Signs such as fever, facial pain, discolored or bloody discharge, or a change in vision indicate that a potentially serious infection is present. A primary care physician can perform an initial assessment, but an Ear, Nose, and Throat (ENT) specialist is often required for a definitive diagnosis.
The diagnostic process typically involves a physical examination of the external nose and a thorough look inside the nasal passages using a small, lighted instrument called an endoscope. For symptoms suggesting deeper infection, imaging studies like a computed tomography (CT) scan may be used to visualize the sinuses and check for blockages or fluid retention. Treatment is always tailored to the specific cause identified.
For surface issues, the recommendation may involve topical antibiotic ointments or a simple refinement of the daily hygiene routine. Internal bacterial infections, such as acute sinusitis, are commonly treated with a course of oral antibiotics, often alongside nasal saline irrigation to flush out stagnant mucus. For structural issues or chronic conditions like atrophic rhinitis, treatment may involve surgical correction or long-term management with specialized nasal sprays and moisturizing rinses.