Paronychia: what is it, symptoms, causes, treatment, prognosis

What is paronychia?

Paronychia Is an infection of the proximal and lateral folds of the nails, including the tissue that borders the root and sides of the nail. This condition can occur spontaneously or after injury. Paronychia is one of the most common hand infections. Paronychia occurs as a result of a breakdown of the protective barrier between the nail and the nail fold, as a result of which bacteria appear, causing inflammation in this area. Acute paronychia is usually limited to one nail; however, if the condition is caused by a drug, it can affect many nails.

To diagnose paronychia, your doctor needs a detailed history and physical examination to check for swelling and painful nail fold, as there are no laboratory tests or images to put diagnosis. The infection is usually simple; however, the presence abscess not always obvious. A dermatologist can manage paronychia in most cases, but in the rare cases where deep structures and / or bones are affected, an orthopedic consultation may be required.

Signs and symptoms

Paronychia is usually acute, but chronic paronychia can also occur.

Acute paronychia develops along the edge of the nail (lateral and posterior nail folds). After a few hours or days, with acute paronychia, soreness, an increase in the temperature of the nails, redness and edema. Pus usually accumulates under the skin along the edge of the nail and sometimes under the nail. Sometimes the infection goes deep into the tissue of a finger or toe and can threaten the loss of a finger or, in extreme cases, an arm or leg. These deep infections mainly occur in patients with diabetes mellitus or other circulatory disorders.

Causes and risk factors

The classification of paronychia is based on the clinical picture:

• Acute paronychia - lasting less than six weeks, painful and purulent; is most often caused by a bacterial infection, especially staphylococci.
• Chronic paronychia - usually caused by mechanical or chemical factors, and sometimes by infectious etiology, such as a fungal infection, especially by species Candida. Risk factors include occupation (dishwasher, bartender, housekeeper), certain medications (gefitinib, erlotinib, sirolimus, everolimus, vemurafenib, dabrafenib and related drugs) and suppressed immune system (diabetes, HIV, malignant neoplasms).

Classification can also be by etiology:

• Bacterial, usually staphylococci.
• A viral, usually herpes simplex virus.
• Fungal, usually Candida species.

Non-infectious causes of paronychia can include contact irritants, excessive moisture, and drug reactions.

Epidemiology

Paronychia is more common in women than in men, with a female to male ratio of 3: 1. Typically, the disease affects manual workers or patients in occupations that require them to immerse their hands or feet in water for a long time (for example, dishwashers). Middle-aged women are most at risk of infection.

Pathophysiology

Paronychia occurs as a result of a violation of the protective barrier between the nail and the nail fold, which is the cuticle. Predisposing factors are trauma (including manicure and pedicure), infections (including bacterial, viral, and fungal), structural abnormalities, and inflammatory diseases (for example, psoriasis). Organisms enter the moist crevice of the nail, which leads to colonization of this area. Most acute paronychias are due to trauma, nail biting, aggressive manicure, artificial nails and may be associated with a stuck foreign body. Infections are most often the result Staphylococcus aureus. Streptococci and pseudomonas are more common in chronic infections. Less common pathogens include gram-negative organisms, dermatophytes, herpes simplex virus, and yeast. Children are prone to acute infections due to habitual nail-biting and finger-sucking, which leads to direct infection of the oral flora, which includes both aerobic bacteria (S. aureus, streptococci, Eikenella corrodens) and anaerobic bacteria (Fusobacterium, Peptostreptococcus, Prevotella, Porphyromonas spp.).

Diagnostics

Paronychia is most often an acute inflammatory process that causes painful redness and swelling of the lateral nail fold, and is primarily diagnosed on the basis of clinical manifestations. The patient usually seeks help within the first few days after infection due to pain. The history may include recent trauma, infection, structural abnormalities, or inflammatory conditions. Occupation and work environment are important findings in the medical history; housewives, bartenders, and dishwashers seem to be predisposed to developing chronic paronychia. The history must include any debilitating diseases such as diabetes and HIV. A list of medications the patient is currently taking can help determine the cause of chronic paronychia.

Physical examination for acute paronychia reveals an erythematous, swollen, and painful lateral nail fold. If present abscess, the paronychia will show a larger than expected blanching area and will require drainage. In chronic paronychia, the nail fold may be red and swollen. The nail roller may feel wet and the nail plate will thicken and discolor. Other common manifestations of chronic paronychia include retraction of the proximal nail fold, nail degeneration, and cuticle loss.

Treatment

Paronychia is usually treated with an incision and drainage or antibiotics. If there is inflammation without an obvious abscess, treatment may include warm baths with water or antiseptic solutions (chlorhexidine, povidone iodine) and antibiotics. The warm soak should continue for 10 to 15 minutes several times a day. There is no conclusive evidence that topical antibiotics are recommended versus oral antibiotics, and this may depend on the clinician based on experience. The antibiotic used must have a staphylococcal coating. Topical antibiotics can be triple antibiotic ointment, bacitracin, or mupirocin.

Oral antibiotics may be prescribed for patients who have not received topical treatment or in more severe cases; dicloxacillin (250 mg four times a day) or cephalexin (500 mg three to four times a day). Indications for the use of anaerobic coated antibiotics include patients requiring oral vaccination; this will require the addition of clindamycin or amoxicillin-clavulanate. If the patient has risk factors for methicillin-resistant Staphylococcus aureus (including but not limited to: recent hospitalization, recent surgery, HIV /AIDS, the person is in a long-term care facility), an antibiotic with appropriate coverage is selected. Options include trimethoprim / sulfamethoxazole (1–2 tablets twice daily), clindamycin (300 to 450 mg four times daily), or doxycycline (100 mg twice daily).

If there is an abscess, the infection will require drainage. Incision and drainage are usually performed with a # 11 scalpel, and the blade is inserted under the eponychial fold (lateral nail fold) until pus begins to drain. Local anesthesia usually helps provide comfort and complete drainage. The abscess requires a saline flush, and if the abscess and incision are large, the doctor may apply gauze over it to continue draining. If the abscess spreads to the nail bed or is associated with an ingrown toenail, partial removal of the nail plate may be required. If an abscess is present and not drained, it can spread under the nail to the other side and lead to a perforating abscess. In this case, complete nail removal may be required to ensure adequate drainage and treatment. After incision and drainage, warm soaks are performed to aid further drainage, keeping the wound open and preventing secondary infection. The patient should consult with a physician over the next 24 to 48 hours to ensure drainage and look for signs of an exacerbation of the infection. Incision and drainage are usually adequate treatment for acute paronychia; however, if there is a significant spread of cellulite, oral antibiotics may be prescribed as indicated above.

In chronic paronychia, the patient needs to avoid hand injuries as much as possible. Manual workers are advised to wear gloves. Treatment for chronic paronychia should indicate a fungal etiology. Local and systemic antifungals such as itraconazole and terbinafine, are options, since the etiological factor in the chronic type of the disease is mostly types Candida. It is also necessary to treat other inflammatory diseases of the fingers such as ingrown nails, psoriasis, etc. If chronic paronychia is difficult to treat, other causes, such as malignancy, need to be investigated.

Forecast

With paronychia, the prognosis is usually good. Acute paronychia usually resolves within a few days and rarely recurs in healthy people. Chronic paronychia may persist for several months or longer and may recur in predisposed patients.

Complications

Acute paronychia can cause a serious infection of the hand and spread to the underlying tendons, so appropriate treatment is needed at the initial presentation. This status may require evaluation and treatment by a hand surgeon as it often involves debridement, flushing, or amputation depending on the severity of the infection. The main complication of chronic paronychia is nail dystrophy. This is often associated with brittle, deformed nail plates. Change in nail color is not a rare complication of chronic paronychia.