# Primary Actinomyces in Hand: An Unusual Cause of Osteomyelitis

## TL;DR

This paper presents a rare case of hand osteomyelitis caused by Actinomyces, highlighting the challenges in diagnosing and treating this uncommon infection.

## Contribution

The paper reports a long-term, atypical case of Actinomyces-induced osteomyelitis in the hand, emphasizing diagnostic difficulties and treatment response.

## Key findings

- A 15-year progression of Actinomyces infection in the hand led to severe osteomyelitis.
- Histopathology and culture confirmed the diagnosis of Actinomycosis.
- Combination antibiotic therapy showed favorable response despite delayed treatment.

## Abstract

Actinomycosis is a rare, chronic, and slow‐progressing bacterial infection caused by Actinomyces species. The condition's rarity, nonspecific clinical symptoms, and occasional occurrence in atypical locations often lead to delays in diagnosis, which are critical for initiating timely treatment and preventing further complications. We report the case of an 82‐year‐old man who initially developed pustules on the dorsum of his left hand, which gradually progressed over 15 years into an exophytic mass. Histopathological examination and culture confirmed Actinomycosis, and imaging studies revealed osteomyelitis affecting the carpal and metacarpal bones of the involved hand. Although the delayed diagnosis and treatment resulted in severe osteomyelitis, the patient responded favorably to a combination therapy of Amoxicillin and Trimethoprim‐Sulfamethoxazole.