In patients with diabetic ketoacidosis, which fungal group is most commonly associated with mucormycosis?

• A. Aspergillus fumigatus
• B. Candida albicans
• C. Histoplasma capsulatum
• D. Mucorales (Rhizopus species)

Answer: (D)

Diabetic ketoacidosis creates an environment that impairs neutrophil function and increases free iron due to acidosis, providing ideal conditions for Mucorales to cause infection. The fungi in this group, including Rhizopus species, are the most common culprits of mucormycosis in these patients. This infection is known for rapid, invasive, angioinvasive disease that often starts in the nasal or sinus area and can spread to the orbit or brain. Microscopy shows broad, nonseptate hyphae with wide-angle branching, which helps distinguish it from other fungi like Aspergillus (septate hyphae with acute-angle branching) or Candida and Histoplasma (which cause different clinical pictures). So the fungal group most linked to mucormycosis in the setting of diabetic ketoacidosis is Mucorales, especially Rhizopus.