Hemorrhagic Bullous Lesions Due to Bacillus cereus in a Cirrhotic Patient

Exposed areas such as extremities and digits are most often affected, presumably due to entrance of spores from soil, water, decaying organic material, or fomites through skin microabrasions or trauma-induced wounds.¹ Once in the tissue, the crystalline surface protein layer (S-layer) of the bacilli promotes adhesion to human epithelial cells and neutrophils,⁵ followed by release of virulence factors including proteases, collagenases, lecithinaselike enzymes, necrotizing exotoxinlike hemolysins, phospholipases, and most importantly a dermonecrotic vascular permeability factor.^1,5 Toxins produced by B cereus are similar to those closely related to Bacillus anthracis, the agent of anthrax.^1,2

When large gram-positive bacilli are observed in tissue or wound specimens, initial therapy should address both aerobic (Bacillus species) and anaerobic (Clostridium species) organisms.^1,4,6 Once B cereus is recovered, treatment should rely on susceptibility testing of the isolate. Bacillus cereus produces ß-lactamase, thus penicillin and cephalosporin should be avoided.¹ Vancomycin, clindamycin, aminoglycosides, and fluoroquinolones are the drugs of choice.^1,3,4,6 Daptomycin and linezolid also are active in vitro,¹ but clinical experience with these agents is limited. Necrotic infection or deep tissue involvement requires surgical intervention.

Numerous other organisms can cause cellulitis and soft tissue infections with hemorrhagic bullae.^1,3,6 Streptococci, particularly Streptococcus pyogenes, and occasionally staphylococci are the primary consideration in normal hosts without trauma.^3,6 In immunocompromised patients, including those with cirrhosis, diabetes mellitus, and malignancy, Clostridium perfringens and gram-negative organisms such as Escherichia coli, other enteric bacteria including Pseudomonas aeruginosa, Aeromonas, and halophilic Vibrio species are more frequent.^3,6

We describe a patient with underlying cirrhosis who developed bilateral lower extremity hemorrhagic bullous lesions and sepsis due to infection with B cereus, an emerging cause of serious infections in patients with underlying immunocompromising conditions such as cirrhosis, diabetes mellitus, and malignancy. Hemorrhagic bullae in immunocompromised patients are associated with sepsis and rapidly progressive illness, and rapid treatment is essential. Bacillus cereus should be included as a consideration in the differential diagnosis and management of patients presenting with bullous cellulitis and sepsis.