Disseminated Actinomycosis: Multisystem Mimicry in Primary Care

Michael W. Felz, MD, Michael R. Smith, MD


South Med J. 2003;96(3) 

In This Article

Case Report

A 39-year-old black man presented with a 2-month history of right hip pain and swelling, with worsening limp. He had been evaluated 2 weeks previously in the emergency department, where a diagnosis of osteoarthritis was made. He was treated with anti-inflammatory medication without benefit. He further reported several months of left shoulder pain and nonhealing, painful, cutaneous ulcers located on the left arm, in the left axilla, and in the lumbosacral region. Fatigue and a 40-pound weight loss accompanied the skin lesions. He had been treated elsewhere for a variety of dermatologic conditions, including impetigo, folliculitis, scabies, pediculosis, and herpes simplex infection, without improvement. He denied hip trauma, fever, chills, sweats, pruritus, cough, hemoptysis, dysphagia, diarrhea, other joint pain, risk factors for human immunodeficiency virus (HIV) infection, and ingestion of sharp objects. His wife and three children were in good health.

Physical examination revealed a thin male in no acute distress. His temperature was 38.9°C. Severe periodontal disease was present, along with multiple upper and lower dental caries (Fig. 1). There was no cervical adenopathy. Cardiopulmonary and abdominal examinations were unremarkable. Perineal and rectal examinations revealed bilateral inguinal adenopathy and normal testicular contours. Stool sample was negative for occult blood. Neurologic examination revealed no deficits. A fluctuant, erythematous, warm, tender, 8-cm mass with indurated borders was noted over the right greater trochanter (Fig. 2). Multiple contiguous fresh and fibrotic ulcers were located over the lumbosacral region and buttocks, consistent with recent and chronic fistula formation (Fig. 3). A 3-cm fluctuant, tender mass was detected over the anterior left shoulder. A tender, 1-cm ulcer with surrounding erythema was located in the left axilla (Fig. 4). Multiple tender, indurated, shallow ulcers measuring 1 to 2 cm with erythematous bases were noted over the left forearm (Fig. 5).

Severe periodontal disease, the suspected portal of entry for infection.

Tender, fluctuant, indurated, 8-cm mass over the right hip.

Acute and chronic ulceration and scarring, with fistula formation on the trunk and buttocks.

Erythematous, draining ulcer in the left axilla.

Shallow, indurated ulcer on the left forearm.

A complete blood cell count revealed a hemoglobin level of 6.7 g/dl, with mean cell volume (MCV) of 70 fL. Platelet count was elevated at 631,000/mm3. The white blood cell count was 13,000/mm3, with 84% neutrophils, 10% lymphocytes, 5% monocytes, and 1% eosinophils. The erythrocyte sedimentation rate (ESR) was elevated (>150 mm/h). C-reactive protein level was 23.8 mg/dl (normal, 0-1). Blood chemistry test revealed a low albumin level of 2.2 g/dl and evidence of iron deficiency. Serum protein electrophoresis revealed decreased albumin level, with increased -2- and -globulin levels. Total serum immunoglobulin levels were normal, rapid plasmin reagin test was negative for syphilis, and the patient was HIV-negative. A tuberculin skin test and blood cultures were negative for microorganisms.

X-rays of the right hip revealed soft tissue swelling and fluid accumulation corresponding to the fluctuant area noted on physical examination. There was no bone destruction. Computerized tomography (CT) scans revealed abnormally enhancing fluid collections and soft tissue masses throughout the musculature of the right hip, right gluteus maximus, and proximal right thigh, all suggestive of abscess or neoplasm. Similar findings involved the contralateral iliopsoas muscle, extending into the extraperitoneal soft tissues of the left pelvis, paraspinous musculature, and presacral space. These findings were consistent with myositis, cellulitis, fasciitis, and small sinus tracts. Soft tissue effusion over the right hip was documented (Fig. 6), with focal fluid collections in the right buttock suggestive of abscess or hematoma. A large soft tissue density (Fig. 7) encircled the midportion of the esophagus with tracking to the right hemidiaphragm, suspicious for tumor or an infectious process. Numerous small pulmonary densities were scattered throughout the right upper, lower, and middle lobes. A 1.5-cm lesion was noted in the right kidney, representing an abscess or complex cystic lesion. Prominent bilateral axillary and inguinal adenopathy and soft tissue stranding were consistent with an infectious process or malignancy.

Computed tomographic scan showing effusion over the right hip (arrow) and soft tissue abscesses in right buttock (arrowheads).

Computed tomographic scan documenting a large mass (arrowheads) encircling the esophageal lumen (arrow).

Initial diagnostic considerations for the dermatologic findings included cellulitis, actinomycosis, nocardiosis, or fungal infections, such as blastomycosis, coccidioidomycosis, histoplasmosis, or cryptococcosis. The orthopedic manifestations were thought to represent osteomyelitis, septic arthritis, or tuberculosis. Esophageal, pulmonary, and myofascial findings with adenopathy were suggestive of lymphoma, metastatic carcinoma, endocarditis, mycobacterial infection, HIV infection, or some other form of immunodeficiency.

Bloody material aspirated from the left shoulder abscess contained many discrete, lemon yellow sulfur granules (Fig. 8). Microscopic examination of a crushed granule demonstrated branching, beaded, Gram positive, filamentous rods in tangled clusters (Fig. 9).

Sulfur granules in purulent aspirate from the left shoulder abscess.

Gram stain revealing clusters of Gram-positive, beaded, filamentous, branching bacteria.

Orthopedic consultants felt that osteomyelitis was unlikely, based on the radiographic findings of normal bone. Aspiration of the right hip mass produced 3 ml of serosanguinous fluid, subsequently found to be negative for microorganisms with Gram stain and culture. Infectious disease consultants suggested that disseminated actinomycosis was highly likely. A periodontal portal of entry was postulated, followed by widespread visceral involvement. Subsequent culture of aspirated shoulder discharge yielded Actinomyces species that could not be further characterized by laboratories at the Medical College of Georgia or by the Centers for Disease Control and Prevention in Atlanta. Cultures for acid-fast bacteria and Nocardia species were negative.

Therapeutic recommendations included 6 weeks of parenteral treatment with ceftriaxone (2 g/d), followed by 1 year of oral amoxicillin therapy (1,500 mg/d). On hospital Day 5, a percutaneous catheter was inserted into the superior vena cava for home administration of IV antibiotics, and the patient was discharged home. Follow-up revealed that the hip pain had resolved and all cutaneous ulcers had healed within 2 weeks. Within 4 weeks, the anemia had resolved and the ESR had normalized. Follow-up chest CT 2 months after discharge showed complete resolution of the paraesophageal mass. The patient reported increased vigor and appetite, a 45-pound weight gain, and full return to work as a cook.