Acute Paronychia: The Dark Side of Nail-biting
Case:
A 36-year-old female with no significant past medical history presents with pain and swelling to her right middle finger that has worsened over the last 3 days. The patient endorses irritation of the distal aspect of her right 2nd digit surrounding the nail bed. She is still able to move her finger but has pain with grasping. She denies fevers, paresthesias, numbness, weakness. She has never had similar symptoms but endorses chronic nail-biting. She was hoping the symptoms would improve but they have worsened, leading to her presentation to emergency department.
Vitals:
HR: 67 BP: 129/74, RR: 12, T: 36.7 C, SpO2: 99% on room air
Patient is hemodynamically stable.
Physical exam:
General: Well-appearing female in no acute distress
MSK: Erythema and swelling of right 2nd digit distal to DIP joint, area of fluctuance surrounding entire nail bed, no active bleeding or drainage. Tender to palpation. Blanching of fluctuance when pressure is applied digit
Neurovascular: Bilateral radial pulses 2+ with good capillary refill of all digits, sensation intact in all digits, 5/5 strength of right 2nd digit PIP and DIP joint
Figure 1: Photograph of a fingertip demonstrating an abscess, which is evident from the blanched area caused by simple digital pinch pressure. (Courtesy of Robert Starch, MD, New York, NY.)
Diagnosis:
Clinical history and physical exam show acute paronychia with abscess of the right 2nd digit.
Discussion:
Acute paronychia is an acute infection and inflammatory process adjacent to the nailbed. It typically develops following minor trauma that disrupts the nail fold barrier. [1] Symptoms have generally been present for less than 6 weeks. If a paronychia has been present for longer than 6 weeks, it is considered a chronic paronychia. Chronic paronychia is usually associated with chemical and environmental irritants. Another subtype of paronychia is chemotherapy-associated paronychia, typically caused by EGFR inhibitors and taxanes 4 to 8 weeks after initiation. [2]Risk factors for acute paronychia include manicuring, nail biting, thumb sucking, and nail picking. Trauma-induced paronychia generally involves one digit. Skin flora such as staphylococcus aureus and streptococcus pyogenes are the most common organisms, however, pseudomonas aeruginosa and other gram-negative bacteria may be seen in acute on chronic infections. Oral flora such as streptococci, S. aureus, Eikenella corrodens, Fusobacterium, Peptostreptococcus, Prevotella and Porphyromonas spp may also be present in trauma induced by nail-biting. [3]
Acute paronychia is a clinical diagnosis. Clinical clues include a history of local minor trauma and purulent fluid collection around the proximal or lateral nail folds. If fluctuance extends around all three nailbeds, it is termed a “runaround infection”. [1] An abscess may be present. The digital pressure test can be used to assess for an abscess. If mild pressure to the distal finger pad produces blanching on the paronychium, an abscess should be suspected. [4] There is generally no neurovascular compromise. Other conditions to keep on the differential diagnosis while evaluating an inflammatory process of the digit include felon, herpetic whitlow, psoriasis, proximal onychomycosis, Reiter syndrome, pemphigus vulgaris.
The initial approach to treatment is to determine if an abscess is present. If an abscess is present, incision and drainage under a digital block with culture of purulent material is generally indicated. A partial or complete nail plate removal may be needed if the abscess extends to the nailbed. Following the procedure, frequent warm soaks are advised. Use of oral antibiotics is controversial in the literature. In one study that followed 46 patients who underwent surgical excision without post-operative antibiotics for either uncomplicated paronychia, felon, or both, 46 patients healed without complication. [5] However, antibiotics are generally advised for severe cases or in immunocompromised patients. First line agents include antistaphylococcal agents such as cephalexin. If there is a concern for MRSA, sulfamethoxazole/trimethoprim or clindamycin should be chosen. If no abscess is present, frequent warm soaks and topical antibiotics such as mupirocin are usually effective. Long-term complications include dystrophic changes of the nail plate. [6]
Case resolution:
The patient underwent a digital block and nail plate removal in the emergency department. Her nailbed was soaked in warm water and antiseptic for 10 minutes and then was wrapped in a clean bandage. She was discharged with an oral course of cephalexin. His cultures were sent off and grew Staphylococcus aureus. He did not return to the emergency department with any complications.
Takeaway points:
· Acute paronychia is characterized by rapid onset erythema, swelling, and pain surrounding the nailfold, often preceded by local minor trauma.
· Assess for an abscess with the digital pressure test. Blanching indicates the presence of an abscess.
· Acute paronychia with an abscess requires incision and drainage. In severe cases where the abscess extends to the nailbed, nail plate removal may be indicated.
· Antibiotics have not been shown to improve outcomes, except in severe cases and in immunocompromised patients.
Author: Jordan Ozolin, MD is a first-year resident at Brown University/Rhode Island Hospital
Faculty Reviewer: Kristina McAteer, MD
References:
1. Shafritz AB, Coppage JM. Acute and chronic paronychia of the hand. J Am Acad Orthop Surg. 2014 Mar;22(3):165-74. doi: 10.5435/JAAOS-22-03-165. PMID: 24603826.
2. Lee DK, Lipner SR. Optimal diagnosis and management of common nail disorders. Ann Med. 2022 Dec;54(1):694-712. doi: 10.1080/07853890.2022.2044511. PMID: 35238267; PMCID: PMC8896184.
3. Brook I. Paronychia: a mixed infection. Microbiology and management. J Hand Surg Br. 1993 Jun;18(3):358-9. doi: 10.1016/0266-7681(93)90063-l. PMID: 8345268.
4. Turkmen A, Warner RM, Page RE. Digital pressure test for paronychia. Br J Plast Surg. 2004 Jan;57(1):93-4. doi: 10.1016/j.bjps.2003.10.014. PMID: 14672686.
5. Pierrart J, Delgrande D, Mamane W, Tordjman D, Masmejean EH. Acute felon and paronychia: Antibiotics not necessary after surgical treatment. Prospective study of 46 patients. Hand Surg Rehabil. 2016 Feb;35(1):40-3. doi: 10.1016/j.hansur.2015.12.003. Epub 2016 Feb 16. PMID: 27117023.
6. Rigopoulos D, Larios G, Gregoriou S, Alevizos A. Acute and chronic paronychia. Am Fam Physician. 2008 Feb 1;77(3):339-46. PMID: 18297959.