What type of fungus is associated with flare-ups upon cocaine use?

Mucormycosis is the Primary Fungal Infection Associated with Cocaine Use

Mucormycosis (formerly called zygomycosis) is the most significant fungal infection that flares up with cocaine use, particularly affecting the nasal passages, sinuses, and potentially spreading to adjacent structures.

Pathophysiology of Cocaine-Related Fungal Infections

Cocaine use predisposes to fungal infections through several mechanisms:

• Vasoconstriction: Cocaine causes significant vasoconstriction in nasal tissues through blocking presynaptic reuptake of neurotransmitters like norepinephrine and dopamine 1
• Tissue ischemia and necrosis: The vasoconstriction leads to ischemia, necrosis, and subsequent infections of the nasal mucosa, sinuses, and adjacent structures 2
• Direct trauma: Repeated snorting causes mechanical damage to nasal mucosa
• Immunosuppression: Cocaine may impair local immune responses

Clinical Presentation

Mucormycosis in cocaine users typically presents with:

• Nasal congestion or obstruction
• Facial pain or numbness
• Black eschar (necrotic tissue) in nasal passages
• Periorbital edema
• Headache
• Fever
• Visual disturbances if infection spreads to orbital structures
• Neurological symptoms if infection spreads to brain

Diagnostic Approach

When mucormycosis is suspected in a cocaine user:

1. Direct microscopy with optical brighteners is strongly recommended 1
2. Histopathology to identify characteristic non-septate or pauciseptate hyphae with right-angle branching
3. Culture to identify the specific Mucorales species 1
4. Imaging (CT or MRI) to determine extent of disease and identify the "reverse halo sign" which can help differentiate mucormycosis from aspergillosis 1

Other Fungal Infections Associated with Cocaine Use

While mucormycosis is the primary concern, other fungal infections reported in cocaine users include:

• Candida species: May cause disseminated infection, endophthalmitis, or endocarditis 3
• Aspergillus species: Can present as pulmonary infection, endophthalmitis, or CNS infection 3
• Conidiobolus species: Rare but reported to cause disseminated infection with endocarditis in cocaine abusers 4

Treatment Recommendations

For mucormycosis in cocaine users:

1. Immediate antifungal therapy with liposomal or lipid-complex amphotericin B at a minimum dose of 5 mg/kg/day 1
2. Surgical debridement of necrotic tissue is strongly recommended 1
3. Discontinuation of cocaine use is essential
4. Posaconazole 200 mg/day for salvage therapy if initial treatment fails 1
5. Continue treatment until complete response is demonstrated on imaging and permanent reversal of predisposing factors 1

Prevention

The only definitive prevention is complete abstinence from cocaine use. For those who continue to use:

• Harm reduction through avoiding sharing of intranasal equipment
• Recognition that intranasal cocaine use has been independently associated with HCV infection, possibly through sharing contaminated straws 1

Clinical Pitfalls and Caveats

• Mucormycosis is a medical emergency requiring immediate intervention
• Delayed diagnosis significantly increases mortality
• Symptoms may initially mimic sinusitis or other less serious conditions
• Amphotericin B deoxycholate should be avoided due to severe adverse effects 1
• Treatment must continue until complete resolution of infection and permanent cessation of cocaine use

Remember that mucormycosis has a high mortality rate (24-49%) even with appropriate treatment 1, making early diagnosis and aggressive management essential for survival.