A 55-year-old male, manual laborer, who is an alcoholic presented with a history of multiple swellings over left leg, of 8 years duration. There was preceding history of trauma with a nail on the left sole following that a boil-like lesion appeared at the site of injury. The lesion progressed gradually over 8 years spreading to foot, calf and thigh with multiple discharging sinuses and occasionally granules. There was no history of any chronic illness. He underwent various treatments elsewhere with no improvement.
Cutaneous examination of left leg revealed indurated nodular masses with discharging sinuses over calf, medial aspect of thigh and groin. A few depressed scars were also found [Figure 1]. Systemic examination was unremarkable. Mycetoma, botryomycosis, and actinomycosis were considered as differential diagnoses, and patient was investigated accordingly. Routine blood investigations were normal except hemoglobin% that was low (8.2 g). Ziehl-Neelsen stain, KOH mount, and fungal culture were negative. X-ray of left leg revealed no abnormality. Microscopy of minced tissue after Gram-stain showed Gram-positive cocci in groups and beta hemolysis was noted over blood agar, indicating Staphylococcus aureus as the underlying pathogen [Figure 2]. Histopathological examination after Gram-stain revealed Gram-positive cocci surrounded by eosinophilic material (the Splendore-Hoeppli phenomenon) and further confirming the diagnosis to be botryomycosis [Figure 3]. Lesions healed with scarring after 2 months of therapy with cotrimoxazole [Figure 4].
The term botryomycosis (In Greek: Botrys - bunch of grapes, myces - fungus) is a misnomer as the actual causative agent is not a fungus. Other terms such as actinophytosis, staphylococcic actinophytosis, bacterial pseudomycosis and granular bacteriosis were reported after the discovery of bacterial etiology.
Botryomycosis is a rare disease with few cases being reported worldwide. Review of the literature has shown around 140 published cases of botryomycosis, and cutaneous form of the disease was addressed in 28 articles.
Botryomycosis is caused by many bacteriae, while S. aureus being the most common (approximately 40%), followed by Pseudomonas aeruginosa (approximately 20%). Other reported microorganisms are Escherichia coli, Proteus vulgaris, Bacillus spp. and Actinobacillus lignieresii. The major predisposing factors are skin trauma, postoperative complications, diabetes mellitus, liver disorders, treatment with steroids, alcoholism and cystic fibrosis. However, it can occur even in immunocompetent individuals too.
Botryomycosis can be cutaneous or visceral. Cutaneous form presents as nodules, abscesses, and sinuses with purulent discharge and grains, which heal after several months to leave atrophic scars. Extremities are commonly involved. Devi et al. reported the same on forehead and scalp that is an unusual site. Katkar et al. reported Red grain botryomycosis due to S. aureus. Visceral form usually involves lung and is associated with cystic fibrosis.
Botryomycosis should be differentiated from conditions like mycetoma, actinomycosis and tuberculosis that have similar clinical features. Microscopy of the discharge, culture and sensitivity tests and biopsy helps in confirming the diagnosis. Treatment with prolonged course of antibiotics depending upon culture and sensitivity pattern is recommended, and sometimes surgical intervention might be warranted.
This case is reported for its rarity and its likelihood to be mistaken for diseases such as mycetoma and actinomycosis (which differ in etiology and treatment). Botryomycosis involving almost the entire lower limb is uncommon and moreover, it responded well to cotrimoxazole.