Cutaneous actinomycosis

Cutaneous Actinomycosis is a rare bacterial infection of the skin caused by Actinomyces species, which are gram-positive, anaerobic or microaerophilic bacteria. This condition is part of a broader group of infections known as actinomycosis, which can affect not only the skin but also other parts of the body, including the mouth, lungs, and intestines. Cutaneous actinomycosis typically presents as chronic, hard, and often suppurating lesions that can form sinuses, discharging sulfur granules.

Etiology

Cutaneous actinomycosis is primarily caused by Actinomyces israelii, although other Actinomyces species can also be responsible. These bacteria are part of the normal flora of the human mouth and respiratory tract, but they can cause infection if they penetrate the mucosal barriers, usually due to trauma, surgery, or poor oral hygiene.

Pathophysiology

The infection usually begins when Actinomyces bacteria enter the skin through a break or lesion. Once inside the tissue, the bacteria can form a chronic infection characterized by the formation of abscesses, sinus tracts, and fistulas. The hallmark of actinomycosis is the formation of sulfur granules, which are colonies of bacteria surrounded by inflammatory cells.

Clinical Features

Patients with cutaneous actinomycosis may present with a variety of symptoms, including:

• Chronic, hard, and painful lesions on the skin
• Sinus tracts that may discharge pus or sulfur granules
• Swelling and inflammation around the affected area
• Fever and malaise in some cases

Diagnosis

Diagnosis of cutaneous actinomycosis involves a combination of clinical examination, imaging studies, and laboratory tests. Key diagnostic steps include:

• Microscopic examination of discharge or tissue samples, looking for sulfur granules
• Culture of samples to identify the causative organism
• Imaging studies, such as X-rays or MRI, to assess the extent of the infection

Treatment

Treatment of cutaneous actinomycosis typically involves long-term antibiotic therapy, often with penicillin or a suitable alternative for patients allergic to penicillin. In some cases, surgical intervention may be necessary to drain abscesses or remove infected tissue.

Prevention

Preventive measures for cutaneous actinomycosis focus on maintaining good oral hygiene and promptly treating any oral or skin infections to prevent the spread of Actinomyces bacteria.

Prognosis

With appropriate treatment, the prognosis for cutaneous actinomycosis is generally good, although the condition can recur if not fully eradicated.