Panaritium: symptoms and treatment

A felon is an acute or chronic inflammation of the nail fold and/or tissues of the fingertip or toe, most often caused by bacteria and less commonly by fungi. In Russian clinical practice, felon is also known as a "phelon," a deep abscess of the distal phalanx pulp. The condition begins with pain, redness, and swelling around the nail and can quickly develop into a purulent cavity requiring incision and drainage. The underlying cause is almost always a disruption of the barrier between the nail and the fold due to microtrauma, manicures, or nail biting. [1]

Acute bacterial whitlow develops over hours or days and is often localized to the lateral or proximal nail fold. The chronic form lasts for weeks or months, is punctuated by periods of exacerbation, is more often associated with repeated exposure to moisture and irritants, and may be of mixed bacterial and fungal origin. As the process extends into the fingertip, it forms a "phelon"—a limited but painful abscess in the cellular pulp. [2]

Despite the apparent insignificance of the problem, felon is one of the most common hand infections and a reason for emergency room visits. If left untreated, the infection can spread deeper into the tendon sheaths, joint, or bone, potentially leading to arthritis, tenosynovitis, or osteomyelitis, requiring hospitalization. Therefore, early recognition and appropriate management are critical to preserving finger function. [3]

The modern approach to treatment is simple: if a cavity containing pus is present, it must be drained. If there is no cavity and the inflammation is superficial, local care and, if indicated, systemic therapy are usually sufficient. The choice of method depends on the depth and stage of the infection, risk factors, and the patient's profession. This algorithm is reflected in guidelines on skin and soft tissue infections and in specialized reviews. [4]

Code according to ICD-10 and ICD-11

In the tenth edition of the International Classification of Diseases, felon is coded in group L03 "Erysipelas and other infections of the skin and subcutaneous tissue." For acute periungual inflammation, the L03.01x "Cellulitis of the finger" family is used, specifying the side and finger; the codes are linked to the clinical notation "paronychia/onychия/perionychiya," meaning periungual inflammation is considered a type of cellulitis of the finger. This is convenient for reporting and routing in emergency care. [5]

In the eleventh edition of the classification of diseases, felon is classified under the section on nail disorders and paronychia: EE12.0 "Acute bacterial paronychia" and EE13.2 "Chronic paronychia." This detailing better reflects the nature of the disease (acute bacterial versus chronic multifactorial) and helps differentiate tactics (drainage versus modification of factors and anti-inflammatory care). [6]

Table 1. Correspondence of ICD-10 and ICD-11 codes for panaritium

Classification	Code	Name	Comment
ICD-10	L03.01x	Cellulitis of the finger (paronychia included in the category)	Used with specification of side and finger
ICD-10	L02.5	Skin abscess of the hand	Suitable for "felon" with documented pulp abscess
ICD-11	EE12.0	Acute bacterial paronychia	Acute periungual inflammation
ICD-11	EE13.2	Chronic paronychia	Long-term, often multifactorial inflammation of the perionychia

Epidemiology

Panaritium is one of the most common infections of the distal digits and periungual apparatus. Clinical reviews describe it as "one of the most common hand infections," which is supported by the burden on emergency services and hand surgery. Precise prevalence rates in the general population vary because most mild cases are treated on an outpatient basis and are not included in registries. [7]

Acute felon is more common in people performing manual labor, in workers in "wet" occupations, and in those who bite their nails and carefully remove hangnails. The chronic form is especially common in those who are constantly in contact with water and detergents: hairdressers, cooks, medical personnel, dishwashers, and parents of small children. These observations are consistent across countries. [8]

The age distribution is "double-humped": in adolescents and young adults, acute episodes are associated with manicures and sports injuries, while in middle-aged and older individuals, they are associated with occupational factors and chronic exposure to moisture. In children, felon is less common, but the course is often rapid due to active microtrauma. [9]

The incidence of complications is low with early treatment, but delayed treatment can lead to spread to bone, tendons, and joints. Clinical publications in recent years have described cases of osteomyelitis developing against the background of long-standing chronic panaritium, highlighting the cost of delayed treatment. [10]

Reasons

Acute whitlow is almost always bacterial. Staphylococcus aureus and other staphylococci are most commonly identified; strains resistant to beta-lactam agents are frequently encountered in patients with community contacts. After bites (including cuticular autocannibalism), mixed flora with anaerobes and streptococci are possible. [11]

Chronic paronychia is multifactorial. The underlying mechanism is chronic damage and maceration of the cuticle, which promotes irritation and secondary colonization. In such cases, fungal flora, including Candida yeast, is often a contributing factor, but not the sole cause. Therefore, the chronic process requires not only antimicrobial measures but also adjustments to daily habits. [12]

A "phelone" (distal phalanx pulp abscess) typically begins with a splinter, puncture, crack, or manicure injury. Bacteria then enter the cellular pulp of the finger and quickly form a purulent cavity. Due to dense septa, pressure within the lesion rapidly increases, increasing pain and the risk of ischemia of the fingertip tissue. [13]

Less commonly, felon is triggered by chemical irritants, medications, contact allergens, and dermatoses that disrupt the skin barrier. In such situations, the infection builds on already inflamed tissue, and treatment requires a dual goal: restoring the barrier and eliminating the microbial component. [14]

Risk factors

Key behavioral risk factors include traumatic manicures, cuticle biting, nail biting, and the use of cutting instruments without proper sterility. Microcracks and hangnails are a major gateway for infection, so careful care of the skin around the nail is not cosmetic, but preventative. [15]

Professional risk factors include "wet" occupations and frequent contact with detergents, disinfectants, and water. Constant moisture and maceration loosen the cuticle, creating chronic irritation and setting the stage for colonization by microbes and yeast. Personal protective equipment, barrier creams, and organizational breaks reduce this risk. [16]

Medical factors include diabetes mellitus, peripheral circulatory diseases, and immunodeficiency states. These patients are more likely to have a severe course of infection, slow healing, and ascending spread of infection, so they have a lower threshold for systemic therapy and referral to a hand surgeon. [17]

A special group consists of patients with skin diseases that compromise the integrity of the periungual skin (atopic dermatitis, contact dermatitis, nail psoriasis). In these cases, felon often recurs until the underlying dermatological problems are corrected. [18]

Table 2. Risk factors for felon

Group	Examples	What is dangerous?
Behavioral	Traumatic manicure, cuticle biting	Microtraumas and infection portals
Professional	Frequent wet work, detergents	Maceration, chronic irritation
Medical	Diabetes mellitus, immunodeficiency, circulatory disorders	Severe course, slow healing
Dermatological	Eczema, nail psoriasis	Relapses, chronic inflammation

Pathogenesis

The trigger is a breakdown in the cuticle and nail plate, creating a "pocket" into which bacteria can become embedded. Acute inflammation with swelling and pain develops in response; if drainage is absent, a purulent cavity forms. At this point, drainage becomes the primary treatment, not just systemic medications. [19]

In the pulp of the distal phalanx, thin fibrous septa divide the tissue into compartments. Consequently, pus accumulates under pressure, quickly causing debilitating pain and the risk of tissue ischemia. The distension can compress the vessels, and without timely drainage, there is a risk of fingertip necrosis. [20]

Chronic whitlow is maintained by maceration and contact with irritants; inflammation of the nail fold further destroys the cuticle, creating a "vicious cycle." Candida yeast and bacterial colonization are often present as secondary factors, while the inflammatory component remains the primary one. [21]

If treatment is delayed, infection can spread to the interphalangeal joint, the extensor and flexor tendon sheaths, and then to the bone of the distal phalanx. The complication scenario—ranging from septic arthritis to osteomyelitis—is well described in modern literature and requires inpatient management. [22]

Symptoms

The classic symptoms of acute felon include increasing throbbing pain, swelling and redness at the lateral or proximal nail fold, tenderness to pressure, and sometimes a "yellow" zone of translucent pus. The pain intensifies when lowering the arm and decreases when raising it. [23]

If the process deepens into the pulp, a "phelon" occurs: a sharp, bursting pain in the fingertip, tissue tension, thickening, and tenderness when compressed. Due to the high pressure, the pain is disproportionate to the size of the lesion. Wearing gloves and touching hard objects are extremely unpleasant. [24]

Chronic felon manifests itself as redness and swelling of the nail fold, excessive moisture, pain when pressing, and separation of the cuticle from the nail plate. Over time, the nail may become deformed, developing transverse grooves, brittleness, and dullness. Symptoms are cyclical and intensify after wet work. [25]

Warning signs of progression include fever, streaks of redness across the hand (lymphangitis), limited flexion or extension, pain with passive movement, and severe swelling of the entire distal phalanx. These signs require urgent examination and often surgical intervention. [26]

Classification, forms and stages

Based on location, a distinction is made between periungual felon (paronychia) and pulp abscess of the fingertip (felon). Both forms can coexist, but have different anatomical features and incision options. Correct identification of the form is important for selecting the approach and drainage volume. [27]

Depending on the duration of the process, panaritium is classified as acute or chronic. Acute panaritium develops rapidly, with severe pain and possible cavity formation. Chronic panaritium lasts more than 6 weeks, is maintained by moisture and irritants, is often of mixed origin, and requires long-term barrier care. [28]

The stage is divided into infiltrative (swelling, pain without an obvious cavity), abscess formation (fluctuation, translucent pus), and resolution after drainage. Conservative management is still possible during the infiltrative phase, but if a cavity has formed, surgical drainage becomes the priority. [29]

Bitten felons and cases following manicures are considered separately: mixed flora is more common here, the risk of anaerobes is higher, and therefore the indications for systemic therapy are broader. Documentation of the circumstances is important for selecting an empirical regimen. [30]

Table 3. Forms of panaritium and basic tactics

Form	Main focus	Key feature	First line
Periungual (paronychia)	The ridge at the nail	Pain and swelling at the edge of the nail	Local care, incision as indicated
Pulp abscess (felon)	Pulp of the fingertip	Sharp bursting pain, tension	Incision and drainage
Chronic paronychia	The ridge at the nail	Long-term inflammation, cuticle detachment	Restoring the barrier, eliminating moisture
"Bitten"/after a manicure	Any	Mixed flora	Wider antibiotic coverage

Complications and consequences

If left untreated, a periungual abscess can spread to the pulp, joint, and tendon sheaths. This can lead to septic arthritis, flexor and extensor tenosynovitis, and requires urgent surgical intervention. Each day of delay increases the risk of functional limitations. [31]

Without drainage, "Phelon" can compress the vessels of the fingertip, leading to ischemia and necrosis. Loss of pulp tissue impairs sensitivity and prehension, and in extreme cases, threatens partial loss of the distal phalanx. This is the danger of trying to "suffer" the condition. [32]

Chronic paronychia can lead to nail plate deformity, chronic pain, and dermatitis from constant contact with irritants. Quality of life declines: work becomes painful, and cosmetic changes persist for months. Without lifestyle modifications, the "vicious cycle" persists. [33]

Although rare, cases of long-term chronic inflammation developing into osteomyelitis of the distal phalanx have been reported. This requires long-term antibiotic therapy and sometimes surgical debridement. This prospect is another argument in favor of early and comprehensive treatment. [34]

When to see a doctor

You should seek medical attention within 24-48 hours if pain increases, fluctuation or pus appears, swelling increases, or difficulty bending or straightening the finger becomes apparent. Any sign of a "formed cavity" is a reason to perform drainage in an office or operating room. [35]

Immediate help is required if fever, streaks of redness on the hand or forearm, severe weakness, severe pain with passive finger movement, or inability to straighten or bend the finger occur. These symptoms indicate the spread of infection and impending complications. [36]

Patients with diabetes, immunodeficiencies, circulatory disorders, and preschool-aged children should have a lower threshold for a visit, even with "minor" symptoms. They have a higher risk of complications, and the window for conservative measures is narrower. [37]

It's dangerous to puncture or squeeze a felon on your own. Such actions increase the risk of infection spreading deeper and causing scarring. It's safer and quicker to see a doctor early, where, if necessary, minor surgery can be performed under anesthesia. [38]

Diagnostics

The first step is a clinical examination under good lighting: the location (ridge or pulp) is determined, as is the presence of fluctuation, the degree of tissue tension, and whether movement is limited. For the periungual variant, the doctor gently moves the ridge, assessing the presence of pus in the "pocket" near the nail plate. [39]

The second step is deciding whether pus evacuation is necessary. If there is a cavity or tense pulp ("phelon"), the priority is incision and drainage; systemic medications without drainage rarely provide a cure. If there is no cavity and the inflammation is superficial, local care, warm baths, and, if indicated, antibiotics are prescribed. [40]

The third step is microbiology as indicated. Cultures are performed in cases of relapse, severe infection, immunocompromised patients, bite wounds, and after salon procedures. The results help adjust the empirical regimen and reduce the risk of failure. [41]

The fourth step is instrumental imaging if deep complications are suspected. Ultrasound can confirm the presence of a cavity; radiography is indicated if a foreign body or osteomyelitis is suspected, especially in long-term chronic cases. If signs of tenosynovitis and arthritis are present, the issue should be addressed in consultation with a hand surgeon. [42]

Table 4. Algorithm for diagnosing panaritium

Step	What are we doing?	For what
1	Clinical examination	Determine the shape and stage
2	Drainage decision	Eliminate cavity and pain
3	Sowing according to indications	Specify the pathogen and sensitivity
4	Ultrasound/X-ray as indicated	Exclude a deep process or foreign body
5	Co-management with a surgeon	For phelon, tenosynovitis, arthritis

Differential diagnosis

An inflamed paronychial cyst and granuloma can mimic "pus at the nail," but granulation is often visible on examination, and the pain is less than with a classic abscess. The treatment approach is gentler: eliminating irritants, targeted removal of the granuloma, and barrier care. [43]

Herpetic whitlow (herpetic whitlow) is caused by the herpes simplex virus: vesicles, burning, stinging pain, often without pus; these lesions should not be punctured or incised. Diagnosis is aided by the typical vesicular morphology and a history of exposure to herpes infection; treatment involves antiviral agents and protection against secondary bacterial infection. [44]

An ingrown toenail can present similar symptoms on the lateral fold: localized pain, swelling, and sometimes pus. It is distinguished by its connection to the edge of the nail plate, a dense granulation ridge, and pain sensitivity to footwear. Podiatric correction, unloading, and sometimes partial matrixectomy are important. [45]

Rare "masks" include subungual tumors, melanonychia with inflammation, and nail psoriasis with paronychia. In cases of atypia, prolonged progression, and failure to respond to standard measures, dermatoscopy, targeted biopsy, and consultation with specialized specialists are indicated. [46]

Table 5. How to distinguish common "doubles" of panaritium

State	Tips for inspection	Basic tactics
Herpetic whitlow	Blisters, burning pain, no pus	Antiviral, no incision
Ingrown toenail	Pain at the edge of the plate, granulation	Podiatric correction
Granuloma/cyst	Granulation, moderate pain	Targeted removal, barrier care
Nail psoriasis/eczema	Chronic inflammation, plate deformation	Dermatological therapy

Treatment

In the infiltrative stage of periungual whitlow without a cavity, local care is the key: warm baths 3-4 times a day, gentle cleansing, drying, barrier creams, and avoiding traumatic procedures. A doctor may prescribe short-term topical antiseptics and occlusive dressings. This approach relieves pain and often prevents abscess formation. [47]

If there are signs of a bacterial process and significant swelling, but no obvious cavity has yet formed, the decision on systemic therapy is made based on clinical evaluation. For bite wounds, "manicure" cases with mixed flora, and in patients at risk, a short course of oral medications with activity against staphylococci and streptococci is initiated; for bites, anti-anaerobic coverage is added. The choice of a specific regimen depends on the region and associated conditions. [48]

Once a cavity has formed at the lateral or proximal nail fold, minimally invasive incision and drainage are performed. An incision is made along the nail edge, avoiding damage to the nail matrix; the cavity is irrigated without excising excess tissue. Following the procedure, daily dressings, soaks, and observation for 24-48 hours with re-evaluation are recommended. This quickly reduces pain and the risk of spread. [49]

"Felon" almost always requires surgical drainage. Under local anesthesia, a longitudinal or lateral incision is made, preserving the vascular bundles. The pulpal septa are carefully destroyed, and drainage is placed for 24-48 hours. Without drainage, the risk of ischemia and necrosis is significantly higher, and tablets alone almost never lead to a cure. [50]

Antibiotics are prescribed more frequently for felon: in cases of severe cellulitis around the wound, fever, in patients with diabetes and immunodeficiency, and for bite wounds. In outpatient practice, medications active against Staphylococcus aureus and streptococci are selected, and if there is a risk of resistant strains, local susceptibility data are taken into account. The course of treatment is usually 5-7 days, with adjustments based on the clinical situation. [51]

Postoperative care includes elevating the hand, applying dry dressings, changing the dressings daily, maintaining cleanliness, and early mobilization without weight-bearing. Pain management is important: cooling during the first 24 hours and, if necessary, oral painkillers. If pain worsens after 48 hours, pus appears, or redness spreads, a follow-up examination is necessary. [52]

Chronic paronychia is treated differently: the focus is on restoring the barrier and eliminating chronic moisture. The patient is prescribed a "dry hands" regimen: cotton gloves under protective gloves, the use of barrier creams before and after contact with water, avoiding cuticle removal, and a delicate manicure. During exacerbations, anti-inflammatory topical agents are prescribed; antifungal agents are added if yeast is confirmed to be involved. [53]

If mixed flora is suspected or relapses occur, targeted culture of the material is useful. This helps avoid "one-size-fits-all" regimens, shorten treatment duration, and reduce the risk of adverse effects. This is especially important in patients with a long history of chronic inflammation and nail deformities. [54]

Patient education is a mandatory part of the plan. The doctor explains why it's not advisable to "prick" or pierce lesions at home, how to properly perform soaks and dressings, when to return to manual work, how to protect the skin from detergents, and how to gradually return to normal activity after the procedure. This "educational prescription" reduces the frequency of repeat interventions and accelerates functional recovery. [55]

If signs of spread to the joint, tendons, or bone are detected, the patient is referred to a hand surgeon and treated in a hospital setting. There, extensive surgical debridement, intravenous therapy, and a physical therapy program are possible. Timely treatment for "red flags" is essential for full functional recovery. [56]

Table 6. When to add systemic medications to local measures or drainage

Situation	Examples	Tactics
Systemic signs	Fever, chills, tachycardia	Drainage plus systemic therapy
Common cellulite	Diffuse redness around the lesion	Drainage plus systemic therapy
Risk factors	Diabetes mellitus, immunodeficiency	Wider spectrum, longer observation
Bite/"manicure" wounds	Mixed flora, anaerobes	Expand coverage, seeding

Prevention

Prevention begins with daily habits: avoid cutting or picking at cuticles, avoid biting nails, carefully remove hangnails with sterile instruments, and moisturize your hands after washing. These steps maintain the integrity of the nail barrier and dramatically reduce the risk of infection. [57]

When working wet, use gloves that fit properly, cotton linings under rubber gloves, barrier creams before contact with water, and restorative creams afterward. It's helpful for employers to organize a glove change schedule and breaks for hand drying. Such small steps reduce the risk of chronic hand irritation. [58]

A manicure should be gentle: use sterile instruments, avoid aggressive cuticle trimming, gently push back cuticles with an orange stick, and carefully trim hangnails. If signs of inflammation appear, it's best to postpone your visit to the salon and consult a doctor. [59]

For people with underlying eczema and psoriasis, individualized care plans are helpful to control dryness, cracking, and inflammation around the nails. Once the barrier is stable, recurrences of felon become rare. [60]

Forecast

With early treatment and proper management, most cases of acute panaritium resolve within 7-14 days. After drainage, pain quickly subsides, and finger function returns within a few days, provided dressings and a gentle regimen are followed. [61]

The outcome is worse in patients with undrained phelonions, in patients with diabetes and immunodeficiencies, and in those with delayed treatment. These groups have a higher risk of dissemination to joints and bone, and a greater likelihood of long-term disability and functional limitations. [62]

Chronic paronychia is benign but persistent: without correction of lifestyle factors and barrier restoration, it tends to recur. With a proper care program, education, and elimination of irritants, the prognosis is favorable, although cosmetic normalization of the nail may take months. [63]

After recovery, it's important to maintain preventative habits and avoid injury to avoid returning to procedures and antibiotics. Patient education is the best "insurance" against relapse. [64]

Frequently Asked Questions (FAQ)

Is it possible to treat a felon without an incision?
If there is no purulent cavity, local care and, if indicated, a short course of systemic medications are often sufficient. If a cavity does exist, it must be drained; otherwise, pain and the risk of complications persist. [65]

Does everyone need antibiotics
? No. For superficial lesions without a cavity and without systemic symptoms, local measures are often sufficient. Antibiotics are indicated for widespread cellulitis, in high-risk patients, for bite wounds, and for "felone" in addition to drainage. [66]

How urgent is it to operate on a "felon"?
As soon as possible: increasing pressure in the pulp threatens ischemia and necrosis of the fingertip. Drainage under local anesthesia usually quickly relieves pain and prevents complications. [67]

How does a herpetic whitlow differ from a purulent whitlow?
With the herpetic variant, there are blisters and a burning pain, but no pus or fluctuation; incisions are contraindicated; antiviral agents and skin protection help. [68]

Is it possible to "stay at home" and wait?
Waiting without an examination is risky if the pain increases, fluctuations appear, movement is limited, or the temperature rises. In such cases, an examination and possibly drainage are necessary. [69]

Additional tables

Table 7. Red flags - when to see a doctor immediately

Sign	Why is this dangerous?	The next step
Severe bursting pain in the fingertip	Possible "phelon" and ischemia	Urgent drainage
Fever, streaks of redness on the hand	Lymphangitis, spread of infection	Expanding therapy, searching for a source
Pain with passive movements	Tenosynovitis, arthritis	Surgical evaluation
Long-term course of more than 6 weeks	Chronic process, risk of nail deformation	Barrier care, dermatological tactics

Table 8. Code selection in typical scenarios

Scenario	ICD-10	ICD-11
Acute periungual felon, unspecified	L03.01x "Finger Cellulite"	EE12.0 "Acute bacterial paronychia"
Chronic paronychia in a wet-worker	L03.01x (by localization)	EE13.2 "Chronic paronychia"
Pulp abscess ("phelon") with drainage	Additionally L02.5 "Skin abscess of the hand"	Nail infection code not applicable; clinical description "felon", accompanying code for abscess