Botryomycosis.

Botryomycosis is a rare chronic bacterial granulomatous disease that usually involves skin and rarely viscera. Main etiological agent is Staphylococcus aureus and less commonly Pseudomonas spp., Escherichia coli, Proteus spp., Streptococcus spp. We here report a case of 32-year-old male with polymicrobial botryomycosis on forehead and on frontal scalp. Culture from lesions revealed growth of S. aureus initially. Partial resolution was achieved with cefadroxyl and clavulanic acid, rifampicin, and linezolid. Subsequent repeat culture revealed E. coli sensitive to netilmycin. Slow and steady resolution was achieved with surgical debridement and combination therapy of injectable netilmycin and oral sufomethoxazole and trimethoprim for a prolonged period.

What was known?

The word “Botryo” is derived from Greek word “Botrys” meaning “bunch of grapes.” The nomenclature is a misnomer as it is caused by true bacteria and not by fungus (myces = fungus). The disease was originally discovered by Otto Bollinger in 1870 and its name was coined by Sebastiano Rivolta in 1884. In 1919, the bacterial origin of the infection was discovered.

Introduction

Botryomycosis (or bacterial pseudomycosis or pyoderma vegetans) is a rare chronic bacterial granulomatous disease that usually involves skin and rarely viscera.[1] Most common causative bacteria is Staphylococcus aureus and occasionally Pseudomonas spp., Escherichia coli, Proteus spp., and Streptococcus spp.[2]

Case Report

A 32-year-young man presented with 1 year history of multiple erythematous fluctuant skin lesions, most of which were discharging purulent material. The lesions were located over forehead and frontal scalp [Figure 1]. He had a history of road traffic accident 2 years back with trauma over forehead. Local cutaneous examination revealed nodular, cystic, granulomatous, indurated, and tender lesions. Vital signs were normal. Systemic examination did not reveal anything significant to the case.

Figure 1

Multiple fluctuant nodulocystic lesions at the time of presentation

No reports suggestive of immunosuppression or diabetes mellitus were noted. On culturing, the isolate grew as a golden-yellow pigmented, opaque colony that was later diagnosed as S. aureus by Gram staining, and catalase and coagulase tests. Ziehl – Nelssen staining, KOH preparation, and fungal culture were negative. Skull and chest X-ray revealed no abnormality. Biopsy revealed features of botryomycosis.

As per sensitivity reports, the treatment was modified to oral cefadroxyl and clavulanic acid (500 mg, twice daily) for 10 days along with rifampicin (600 mg, once daily) for first 2 weeks. As the patient developed new lesions, repeat culture was tested to reveal growth of E. coli. Based on the sensitivity reports, the patient was treated with injectable netilmycin (300 mg/3 ml, once daily) for 15 days with oral sulfomethoxazole-trimethoprim (double strength, twice daily). One session of surgical debridement was performed for the solitary larger granulomatous mass, non-responsive to treatment. Slow and steady resolution was achieved during 2 months of the patient's hospitalization. Presently, patient is continuing oral sulfomethoxazole-trimethoprim (double strength) and is on regular follow-up with remarkable improvement [Figure 2].

Figure 2

Improvement after 2 months of therapy

Discussion

Botryomycosis may present in cutaneous or visceral forms. Cutaneous form is a chronic persistent condition that presents with chronic, suppurative, and granulomatous skin lesions as in our patient. It may be preceded by trauma.[2] Most cases present with nodules, abscesses, and sinuses with purulent discharge (similar to that in our patient). Visceral form is usually with pulmonary involvement,[3] which is associated with cystic fibrosis and reaches skin forming sinuses and irregular masses; this was ruled out in our patient by chest x-ray. Multi-bacterial etiology of botryomycosis in a single patient is rarely detected. Moreover, the involvement of head and neck is quite rare in comparison to extremities, as reported by various authors.[45] The main differential diagnoses of botryomycosis are exogenous actinomycosis and eumycetoma, which clinically present enlarged affected area, fistulas, and drainage of granules, differing with regard to etiology, location, and consistency of the lesions.[6] This case has been presented due to its rarity, unusual site of involvement, and response to netilimycin and co-trimoxazole.

What is new?

Multi-bacterial etiology of botryomycosis in a single patient is rarely detected. Moreover, the involvement of head and neck is quite rare in comparison to that in extremities, as reported by various authors. Hence, we present this case due to its rarity and unusual site of involvement.