Levamisole-Induced Necrotizing Vasculitis

April 22, 2015

How would this 34-year-old man become exposed to levamisole?

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A 32-year-old man with a history of systemic lupus presents to the emergency department with recurrent bilateral ear pain and discoloration. He denies fever, trauma or any recent piercing. Prior episodes have been milder and self-resolving so he never sought medical care, but this time it is much worse and has been going on for 4 days. He denies any other symptoms or any other prior medical problems.

On physical examination, vital signs are normal except for a blood pressure of 168/99 mm Hg. He is afebrile. Head and neck exam is essentially normal except for the ears (Figure), which both appear slightly erythematous with an ecchymotic band through the pinnae. There are no swollen nodes. Lungs are clear and heart sounds are normal. The abdomen is benign. Extremities are without edema and the skin is otherwise clear.

Laboratory findings include normal metabolic panel but the complete blood cell (CBC) count shows mild pancytopenia and sedimentation rate is elevated at 60 mm/h.

♦ What question should you ask him? (Hint: think social history)

♦ What other testing might be helpful? 

♦ What is your diagnosis?

♦ What treatment course would you recommend?
 

Answers:

♦ Ask about cocaine use and/or perform a toxicology screening.

♦ This patient did not have polychondritis, an autoimmune disease that primarily affects cartilage, as initially suspected, but rather necrotizing vasculitis and pancytopenia from levamisole, an animal deworming medication that is often used to cut cocaine.

♦ Treatment for pancytopenia or necrotizing vasculitis from levamisole is supportive.

Cocaine toxicity is well known to most medical providers. Complications may include hypertensive emergency, myocardial infarction, dysrhythmia, aortic dissection, stroke, and rhabdomyolysis. Few providers however are aware of the complications of levamisole, a veterinary deworming agent used to cut about 70% of cocaine in the United States. It can cause pancytopenia and/or systemic thrombosis that usually affect areas with limited blood supply, such as the ears.

Treatment for cocaine toxicity depends on the specific complication, but usually involves benzodiazepines and IV fluids, plus additional agents if blood pressure needs to be lowered further. It is important to avoid the use of β-blockers because they can lead to a paradoxical worsening of blood pressure (unopposed alpha), as well as agents that can prolong the QT interval. Treatment of levamisole toxicity is supportive. In most cases, no specific intervention is required, but if pancytopenia is severe such may not be the case.

This patient was discharged home on a “cocaine-free diet” with repeated CBC count ordered in 2 days; findings showed improvement and the patient’s ears also recovered without tissue loss.

 

Basics:Toxicity: MI (¬HR, ¬BP, vasoconstriction…), dysr, aortic dissection, CNS, lung, rhabdo
Levamisole:Fever > Veterinarian deworming agent used to cut ≈70% of cocaine as potentiates high; causes pancytopenia in 5%-10% of chronic users, systemic thrombosis: ear necrosis
Treatment:Benzos, IVF, NTP (verapamil), phentolamine 1-5 mg. Wide-QRS: Bicarb. Long-QT: Mg
Avoid:Beta-blockers, dilantin, agents that can prolong QT intervals or lower the seizure threshold

 

 

POLYCHONDRITIS

Basics:Autoimmune disease that attacks primarily cartilage
Sites:Fever > Ears (spares earlobe), nose, respiratory tract > eyes, valves, joints > CNS, vessels
Diagnosis:3/6 of: outer ear, eye inflammation, inner ear, nose, respiratory tract, polyarthritis
Differential diagnosis:Levamisole-induced necrotizing vasculitis (levamisole is often used to cut cocaine)
Treatment:NSAIDs, steroids, immune suppressants; surgery for some airway & cardiac conditions