Botryomycosis: causes, symptoms, diagnosis, treatment, and prognosis

Botryomycosis, also known as staphylococcic actinophytosis, is a less common disease characterized by chronic, suppurative, granulomatous lesions of the skin and subcutaneous tissue, with sulfur granules in the secretions.

Botryomycosis in animals is manifested by chronic localized abscesses, but internal organs and lymph nodes are merely invaded. Botryomycosis in humans can occur mainly in the head, hands, auricles, and feet. Lesions are often localized, but can also be disseminated to other organs such as the liver, lungs, kidneys, heart, internal organs, prostate, and lymph nodes, mostly in the lungs.


Causes

Most patients are caused by staphylococcus epidermidis, and few are caused by pseudomonas aeruginosa, Escherichia coli, bacteroids, Proteus, Acinetobacter, Neisseria, streptococcus, and pseudomonas cepacia. Negative results are present in anaerobic cultures in lesions, and staphylococcus aureus can be found in aerobic cultures.

Pathogenesis

The incidence is often related to the invasion of pathogenic bacteria after trauma, scratches, or surgery. Other predisposing factors include alcoholics, immunodeficiency, and diabetes.


Signs and Symptoms

Cutaneous botryomycosis

Single or multiple abscesses occur in the skin or subcutaneous tissue, forming multiple sinus tracts after rupture of abscesses. Serous fluid flows from the sinus tracts and contains sulfur granules. Skin lesions gradually heal in several months, leaving atrophic scars.

Cutaneous botryomycosis is associated with diabetes, alcoholism, and trauma, mostly in the head, hands, auricles, and feet.

Pulmonary botryomycosis

Pulmonary botryomycosis is characterized by irregular fever, chest pain, expectoration, and night sweats. When the pleura are involved, pleurisy can occur and the empyema can be formed. Flaky shadows can be seen in X-rays examinations, resembling actinomycosis, tuberculosis, and invasive pulmonary cancer, but staphylococci can be isolated in lung biopsy.

Pulmonary botryomycosis is more common in individuals with low immunity.

Cerebral botryomycosis

The most common manifestation is cerebral abscesses.

Other botryomycosis

Hepatic and renal botryomycosis is often misdiagnosed as hepatic and renal tumor. Sulfur granules can be seen in histopathology. Gram-positive cocci and few Gram-negative bacilli can be seen in the granules. Botryomycosis in the reproductive tract is also seen, but actinomycetes infection is rare. In addition, gastroparietal abscesses caused by uterine botryomycosis and gastrointestinal bleeding caused by gastrointestinal botryomycosis are present.


Histopathology

Chronic granulomatous lesions with visible sulfur granules are present. Neutrophils, lymphocytes, eosinophils, plasma cells, and fibroblasts are scattered around granulomas. Some foreign body giant cells are also visible. The purulent center of granulomas is composed of sulfur granules, covered by neutrophils. Eosinophils are surrounded by clusters of staphylococci. Positive results are present in PAS staining of necrotic lesions.


Diagnosis

On the basis of clinical manifestations such as sulfur granules and multiple sinus tracts, results of bacteriological examinations, and characteristic histopathology, a definitive diagnosis can be provided.


Treatment

Antibiotics are effective and surgical resection is required for chronic intractable lesions.


Prognosis

The prognosis is generally good, but poor if with visceral lesions.