Picture Blog: Collar Button Abscess (Answer)

Collar Button Abscess
Answer post to “Picture Blog: Hand Pain“

Fig. 1. Characteristic “V” shape, fingers abducted (original photograph)

Diagnosis

This patient has a collar button abscess with necrotizing fasciitis. A collar button abscess is an abscess of the interdigital web space. There is typically a recent history of trauma to the area, most likely a laceration or puncture wound causing inoculation to either the volar or dorsal aspect. It can be diagnosed on physical exam alone by the characteristic “V” shape caused by the abduction of the adjacent fingers as seen above. The tip of the “V” will point to the location of the abscess.[1]

Fig. 2. More examples of the characteristic “V” shape.[1]

Complications

You will only see abduction of the adjacent fingers once the infection has reached a deep space of the hand, so the characteristic “V” shape should trigger an immediate hand surgery consult. Deep space infections can lead to amputation and sepsis. Necrotizing fasciitis, in particular, has a mortality rate between 23-76%, regardless of early amputation.[2]

Initial treatment

IV antibiotics and urgent orthopedic evaluation for surgical irrigation and debridement. Surgical intervention is always indicated for a collar button abscess.[1]

Choosing an antibiotic

Most common pathogens: S. aureus and group A strep. There is growing concern for the rising rates of MRSA in the community.[3] In diabetics, also cover gram negatives and anaerobes.

Initial empiric therapy (most common)[2,4]:

• Vancomycin + piperacillin/tazobactam OR
• Vancomycin + ampicillin/sulbactam

Fig. 3.[5] The interdigital webspace is limited on the volar side by aponeurotic attachments. Infection will therefore spread dorsally into one of the deep spaces – thenar, hypothenar, or mid-palmar depending on location.[6]

Fig. 4. A rim enhancing abscess in the digital web space between the first and second MCPs with dorsal extension.[6]

Special thanks to residents of the Kings County Orthopedics department for the idea for this post!

References

1. Kalbfell E, Adams NS, Cullen WT. Collar Button Abscess. Eplasty. 2016;16. Accessed December 7, 2020. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4753838/
2. Osterman M, Draeger R, Stern P. Acute Hand Infections. J Hand Surg. 2014;39(8):1628-1635. doi:10.1016/j.jhsa.2014.03.031
3. Tosti R, Ilyas AM. Empiric Antibiotics for Acute Infections of the Hand. J Hand Surg. 2010;35(1):125-128. doi:10.1016/j.jhsa.2009.10.024
4. Abrams and Botte. Hand Infections: Treatment Recommendations for Specific Types. J Am Acad Orthop Surg. 1996;4(4):219-230. doi:10.5435/00124635-199607000-00006
5. Deep Space & Collar Button Infections – Hand – Orthobullets. Accessed December 7, 2020. https://www.orthobullets.com/hand/6106/deep-space-and-collar-button-infections
6. Patel DB, Emmanuel NB, Stevanovic MV, et al. Hand Infections: Anatomy, Types and Spread of Infection, Imaging Findings, and Treatment Options. RadioGraphics. 2014;34(7):1968-1986. doi:10.1148/rg.347130101

The following two tabs change content below.

• Bio
• Latest Posts

nicanthony

Associate Editor at County EM Blog

Nicole Anthony is a Kings County/SUNY Downstate EM Resident in the Class of 2023 whose prior life included EMS, a failed app, and a Creative Writing minor. Most of her heart is in Prague, but you can also find a part of it in the 2 Hallway column.

Latest posts by nicanthony (see all)

• Abortion Care in the ED - May 23, 2023
• DNR Orders in the Suicidal Patient - September 22, 2022
• Sono of the Week: Neck Swelling - August 2, 2022