Paronychia is an infection around the nail folds, the skin surrounding your fingernails and toenails. It manifests in two particular forms, namely, acute and chronic paronychia. In this article, the aim is to provide a comprehensive look and understanding of paronychia’s causes, symptoms, treatments, diagnosis and prevention.
What is Paronychia?
Paronychia is an infection affecting certain parts of the fingers and toes nails, including the areas near where the nail meets the skin (proximal) as well as the sides of the nail extending away from the body (lateral). This means it mainly affects the base and sides of the nails. This condition arises when the protective barrier between the nail and the nail fold is damaged, allowing bacteria, fungi, or viruses to enter the fold, causing inflammation and infection. It can spontaneously occur or from trauma or manipulation. In some cases, immunosuppressed or genetic predispositions make individuals susceptible to infection.
Paronychia is among the most common infections of the hand, but can also affect the toenails. Susceptibility to paronychia is caused by nail biting, sucking on fingers, manicures and in toes, infections usually begin with ingrown toenails. Other causes of infection include chronic irritation from constant exposure to water and detergents.
Paronychia is classified based on its clinical presentation and duration: acute, which is more common, and chronic, which is uncommon, and in rare cases, infections can be severe. Chronic infections also vary in their etiology, meaning could be a combination of or either bacterial, fungal, viral, or non-infectious pathogen. Individuals with pre-existing immunosuppressed conditions (HIV, diabetes) are also more susceptible to paronychia. Paronychia is more common in women than in men, with a female-to-male ratio of 3 to 11. Usually, they affect manual labor workers or patients in occupations that require them to have their hands or feet kept in water for prolonged periods (e.g., dishwashers).
Acute Paronychia
Acute paronychia develops rapidly, typically within a few days, and usually lasts less than six weeks. It primarily affects the fingernails and is usually caused by bacterial infections, most commonly Staphylococcus aureus. Acute paronychia is usually limited to one nail. It’s usually the result of trauma to the nail fold, such as a cut, hangnail, or ingrown nail, nail-biting, hand injuries and occupations involving harsh environments are often responsible for those who get acute paronychia.
Chronic paronychia develops gradually and persists for six weeks or longer. It can affect both fingernails and toenails and is often caused by a combination of factors, including fungal infections (especially Candida species), bacteria (Streptococci), and irritant exposure (overexposure to water and detergents). Less common causative agents include gram-negative organisms (such as pseudomonas), dermatophytes, herpes simplex virus, and yeast.
Chronic Paronychia
Chronic paronychia is more common in individuals with frequent exposure to water, such as dishwashers, bartenders, and housekeepers. Those who are at high risk of developing chronic paronychia depend on factors including occupation (dishwasher, bartender, housekeeper), certain medications, and immunosuppression (diabetes, HIV, malignancy).
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Other Etiological Classifications
Bacterial paronychia is primarily caused by Staphylococcus aureus, a common bacterial pathogen responsible for skin infections. However, other bacteria such as Streptococci and Pseudomonas can also contribute, particularly in cases of chronic or recurring infections. This type of paronychia typically presents with localized redness, swelling, and pus formation around the nail fold. It often occurs due to trauma, nail biting, or exposure to moist environments, which encourage bacterial entry. Prompt treatment with antibiotics is usually effective, though chronic cases may require more targeted therapy to address resistant or atypical bacterial strains.
Viral paronychia, on the other hand, is most commonly associated with the herpes simplex virus (HSV), leading to a condition known as herpetic whitlow. Unlike bacterial paronychia, this form is characterized by painful vesicles or blisters around the nail bed, often accompanied by systemic symptoms like fever or malaise. It is also contagious and can spread from person to person.
Fungal paronychia, typically caused by Candida species, is more common in chronic cases and is often linked to prolonged exposure to water or irritants like detergents. Non-infectious paronychia can arise from external factors such as adverse reactions to medications
The symptoms of acute and chronic paronychia
Acute paronychia, which usually occurs at the edge of the nail, usually comes with symptoms like pain, warmth, redness, and swelling that develop rapidly over hours or days. In some cases, a pus-filled abscess may form, appearing as a tender bump near the nail. This condition is commonly caused by bacterial infections, often resulting from injuries to the skin around the nails due to biting, picking, hangnails, or even aggressive manicuring.
Chronic paronychia develops more gradually and persists for several weeks or longer, often recurring. The affected nail fold may be swollen, red, and tender, and the cuticle may be damaged or missing. One or more nails may be affected, and changes to the nails themselves can occur. The skin around the nail may feel moist or boggy. Chronic paronychia is often caused by a combination of factors, including fungal infections (such as Candida yeast) and exposure to irritants or allergens.
What Causes Paronychia?
Paronychia is caused by a disturbance to the protective barrier between the nail and the nail fold, which is the cuticle, making it susceptible to infection. Several factors can contribute to this disruption and subsequent infection which are trauma, exposure to irritants and moisture, bad habits, underlying medical conditions and bacterial infections.
Trauma
Trauma from manicures, pedicures, nail biting, hangnails, or the placement of artificial nails can create openings for bacteria or fungi to enter the nail fold. These injuries disrupt the protective barrier between the nail plate and the nail fold, allowing pathogens to colonize the area. Self-inflicted injuries, such as those from improper nail care or insertion of artificial nails, are also common causes of paronychia.
Infections
Acute paronychial infections are the most common in paronychial cases. Staphylococcus aureus is the leading bacterial pathogen responsible for acute paronychia, followed by streptococci and pseudomonas organisms. Fungal infections, particularly those caused by Candida species, are more frequently associated with chronic paronychia. Viral infections, such as herpes simplex virus, can also cause paronychia, though they are less common. In rare cases, paronychia can result from a combination of bacterial and fungal infections.
Exposure to Irritants and Moisture
Excessive exposure to irritants and moisture can lead to the development of paronychia, especially in chronic cases. Frequent exposure to water, chemicals, and other irritants can damage the nail fold, creating an environment conducive to infection. This is particularly relevant for individuals whose occupations involve prolonged exposure to moist environments, such as bartenders, dishwashers, and swimmers. Those who work with their hands and do manual labour are also susceptible to infection. The moist environment facilitates the growth of fungi like Candida, which thrive in these conditions. Additionally, exposure to mild acids, alkalis, or other chemicals can further irritate the skin and increase the risk of infection.
Underlying Medical Conditions
Certain underlying medical conditions can predispose individuals to develop paronychia by weakening the immune system or altering the skin’s barrier function. Individuals with diabetes have a notably high risk factor of being susceptible to paronychia, as it can impede the healing process. HIV infection and other immunocompromised states also predispose individuals to paronychia. Other inflammatory conditions like psoriasis can lead to paronychia due to skin barrier disruption. Rarely, paronychia can be associated with malignancies such as subungual melanoma or squamous cell carcinoma, especially if the condition does not respond to conventional treatment.
Habits
Habits such as nail biting and finger sucking, most prevalent amongst children, introduce bacteria and fungi into the nail fold, leading to infection. Children are prone to acute paronychia due to the direct inoculation of oral flora, which includes both aerobic bacteria (Staphylococcus aureus, streptococci, Eikenella corrodens) and anaerobic bacteria (Fusobacterium, Peptostreptococcus, Prevotella, Porphyromonas.).
How is Paronychia Treated?
Acute Paronychia
Acute paronychia is typically managed with either incision and drainage or antibiotics, depending on the severe nature of the infection. For cases that involve inflammation without a clear abscess, warm soaks can be an effective initial treatment. Soak the affected area in warm water or antiseptic solutions (chlorhexidine or povidone-iodine) for 10 to 15 minutes, repeating several times daily. Alternatively, mix equal parts vinegar and warm water to create acetic acid soaks and use those.
Topical antibiotics, such as triple antibiotic ointment, bacitracin, or mupirocin, are sometimes used. The choice between topical and oral antibiotics often depends on the physician’s preference and the patient’s condition. Antibiotics should provide coverage for Staphylococcus aureus, a common cause of paronychia. For more severe cases or when topical treatments fail, oral antibiotics like dicloxacillin (250mg four times daily) or cephalexin (500mg three to four times daily) are recommended. If anaerobic bacteria are suspected, clindamycin or amoxicillin-clavulanate should be added.
If an abscess is present, it needs to be opened and drained. After this, the area should be thoroughly cleaned with saline solution. A large abscess may require packing with sterile gauze to ensure ongoing drainage. In cases of nail bed involvement or ingrown nails, partial or complete nail removal might be necessary for adequate drainage. Failure to properly drain the abscess can lead to the infection spreading under the nail, forming a “run-around abscess” that demands more extensive intervention.
Patients should continue warm soaks after incision and drainage to keep the wound open, promote drainage, and prevent secondary infection. Patients should follow up within 24 to 48 hours to monitor for signs of worsening infection or inadequate drainage. Clinicians may prescribe oral antibiotics if significant surrounding cellulitis or other complicating factors are present, although incision and drainage are usually sufficient to treat acute paronychia.
Chronic paronychia
Chronic paronychia treatment requires keeping the affected areas dry and avoiding irritants; manual laborers should wear waterproof gloves. Often, treatment targets potential fungal causes. Clinicians frequently use topical antifungal medications, such as ketoconazole cream, to treat Candida species. For more severe cases, they may prescribe oral antifungal medications like itraconazole or terbinafine.
Topical corticosteroids can reduce inflammation but should always be combined with other treatments, as they do not treat the underlying infection. Clinicians should also address inflammatory conditions of the digits, such as ingrown nails or psoriasis, during treatment. Furthermore, addressing any underlying conditions such as diabetes or psoriasis could aid in ensuring the right and effective treatment. Clinicians should consider other potential causes, including malignancy, in cases of chronic paronychia that are difficult to treat. Surgery, involving partial or complete nail removal, may become necessary in severe cases.
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Prevention Strategies
Preventing paronychia involves a few key habits, maintaining good hygiene and avoiding factors that can compromise and damage the nail fold. Keep your hands and feet as clean and dry as possible. Regular handwashing with antibacterial cleanser and thorough drying are essential, particularly after prolonged contact with water containing detergents or chemicals and especially after prolonged immersion in unclean water. For feet prone to sweating or excessive moisture, change socks regularly and use a foot powder to prevent moisture build-up.
It’s also important to practice proper nail care. Avoid nail-biting and picking at the nails or manicuring nail folds. Ensure your manicurist uses sterile instruments and avoids aggressive manicuring and cuticle removal, because this creates an entry point for harmful organisms. Also, avoid the application of nail varnish or false nails until complete recovery from any nail issues.
Protect your hands by wearing gloves for any contact with water, chemicals, and irritants. Waterproof gloves are particularly important when exposed to water, detergents, cleaning fluids, or strong chemicals. It is also important to manage any underlying medical conditions, such as diabetes. For any cuts and scrapes, wash your hands with antibacterial cleanser and bandage if necessary.
Potential Complications
Run-around abscess
Untreated paronychia can lead to significant complications, particularly if infections progress or become chronic. In acute cases, the infection may spread beyond the nail fold, causing a run-around abscess where pus accumulates under the nail plate and extends to adjacent areas. This often leads to the need for complete nail removal to ensure proper drainage. Without intervention, deeper structures like tendons, bones, or joint spaces may become infected, resulting in conditions such as infectious tenosynovitis, osteomyelitis, or felon (pulp space infection). These severe infections may require surgery, intravenous antibiotics, or even amputation in advanced cases.
Nail-related complications
Nail-related complications are common in chronic paronychia. Persistent inflammation disrupts nail growth, leading to nail dystrophy-thickened or brittle nails with yellow or green discolouration. Chronic cases may also cause partial or complete nail detachment (onycholysis) or permanent nail plate deformities. Recurrent infections further damage the nail matrix, increasing the risk of irreversible nail loss.
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Systemic risks
Systemic risks arise when infections spread the blood stream, especially in immunocompromised individuals or those with conditions like diabetes. These patients face higher risks of bacteremia, sepsis, or metastatic infections due to impaired circulation or immune responses. Clinicians should consider rare conditions, such as subungual melanoma or squamous cell carcinoma, in cases of chronic paronychia, especially when lesions do not respond to standard treatments.
High-risk populations
High-risk populations, including manual labourers, diabetics, and individuals on immunosuppressive therapies, are the most vulnerable demographics to paronychia. Diabetic patients are prone to rapid infection progression due to nerve and blood vessel problems, while chronic moisture exposure in occupations like dishwashing or healthcare perpetuates inflammation. Treating paronychia early with medicine (antifungals, antibiotics, or steroids) and avoiding irritants is key to preventing problems. If standard treatments seem ineffective, surgery to remove the nail or part of the nail fold may be necessary. Proactive management of underlying conditions (e.g., psoriasis, diabetes) and strict adherence to preventive measures, like wearing waterproof gloves and avoiding nail trauma can reduce the recurrence of paronychia. Clinicians should evaluate patients with persistent symptoms or recurrent infections for atypical pathogens, malignancies, or systemic diseases to prevent long-term illness.
Differential Diagnosis of Paronychia
Herpetic whitlow, caused by herpes simplex virus (HSV), presents with clusters of painful vesicles which come before burning or itching. Unlike bacterial paronychia, incision is contraindicated due to the risk of secondary infection, and antiviral therapy is the mainstay of treatment. Felons, deep infections of the finger pulp, cause intense pain and tense swelling due to compartmentalized pus, often needing incision for drainage rather than the other approaches used for paronychia. Cellulitis causes widespread redness and warmth without pus and is typically managed with antibiotics rather than drainage
Onychomycosis, a fungal nail infection, causes thickened, discoloured nails but lacks the acute inflammation seen in paronychia. While chronic paronychia may involve Candida, onychomycosis primarily affects the nail plate and is treated through oral antifungals instead of topical treatments. Nail psoriasis looks like chronic paronychia with pits, nail separation, and ridges, but it’s different because it has other psoriasis symptoms and a unique tissue appearance. Inflammatory conditions such as pyoderma gangrenosum and pyogenic granuloma may cause sores or fast-growing tissue. These typically require immune-suppressing treatments instead of antibiotics.
Squamous cell carcinoma (SCC) of the nail bed often appears as long-lasting nail inflammation that doesn’t improve with typical treatments, needing a biopsy to confirm. Similarly, dark spots or unusual nail changes might signal subungual melanoma, another serious condition. Drug-related nail inflammation (linked to medications like EGFR inhibitors or retinoids) often affects both sides and improves when fixing doses.
Conclusion
Key diagnostic clues include the patient’s medical history (e.g. medication use), no improvement with standard therapies, and imaging/biopsies for stubborn cases. Properly distinguishing these conditions ensures correct treatment, avoiding unnecessary surgeries or delays in cancer diagnosis. For example, SCC may mimic chronic infections, while melanoma might be mistaken for benign pigmentation. Early biopsy or imaging helps rule out malignancies, especially when symptoms persist despite standard care.
Paronychia is a common infection of the nail folds that can be effectively managed with proper diagnosis and treatment. Understanding the different types, causes, symptoms, and treatment options is crucial for preventing complications and ensuring optimal outcomes. By following preventive measures and seeking prompt medical attention, individuals can minimize the risk of developing paronychia.
Disclaimer: This information is not intended to be a substitute for professional medical advice, diagnosis or treatment and is for information only. Always seek the advice of your physician or another qualified health provider with any questions about your medical condition and/or current medication. Do not disregard professional medical advice or delay seeking advice or treatment because of something you have read here.
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