Levamisole toxicity mimicking autoimmune disease.
BACKGROUND
Levamisole is present as a contaminant or additive in most cocaine sold in the United States. Cases of agranulocytosis attributed to levamisole-tainted cocaine have been widely described. A vasculopathic reaction to levamisole has also been reported; however, diagnostic features such as antineutrophil cytoplasmic antibody (ANCA) and additional autoimmune marker positivity are not well recognized. As such, many patients are given a misdiagnosis, prompting aggressive and often unnecessary treatment.


OBJECTIVE
We hope to educate practitioners about the clinical and laboratory features of levamisole-induced vasculopathy to ensure accurate diagnosis and management.


METHODS
This was a case series.


RESULTS
Six patients were admitted with purpuric lesions and vasculitic changes on biopsy specimen; 5 of them were given the diagnosis of and treated for autoimmune conditions before their true diagnosis was revealed. All patients had ANCA positivity, and 4 had additional abnormalities in autoimmune markers. All patients reported recent cocaine abuse, and were ultimately given the diagnosis of levamisole-induced vasculopathy.


CONCLUSIONS
This observational study is limited by sample size.


CONCLUSIONS
Patients presenting with purpuric lesions with ANCA positivity should be assessed for cocaine exposure. It is important to recognize that levamisole may not only induce ANCA positivity but also other autoimmune marker abnormalities. Patients can often be treated with less aggressive therapeutic strategies than what is used for primary ANCA-associated vasculitides.
Department of Dermatology, Massachusetts General Hospital, Boston, Massachusetts.
Lauren
L
Strazzula
Katherine K
KK
Brown
Joaquin C
JC
Brieva
Brendan J
BJ
Camp
Hillary C
HC
Frankel
Eugene
E
Kissin
Matthew J
MJ
Mahlberg
Mary Alice
MA
Mina
Miriam K
MK
Pomeranz
Isaac
I
Brownell
Daniela
D
Kroshinsky
D000328:Adult; D000368:Aged; D001327:Autoimmune Diseases / Q000175:diagnosis*; D019970:Cocaine-Related Disorders / Q000150:complications; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007978:Levamisole / Q000633:toxicity*; D008297:Male; D008875:Middle Aged; D014652:Vascular Diseases / Q000139:chemically induced* / Q000175:diagnosis*
D007978:Levamisole
AAV; ACL; ANA; ANCA; antibody-associated vasculitis; anticardiolipin; antineutrophil cytoplasmic antibody; antinuclear antibody; cocaine; double-stranded DNA; dsDNA; granulomatosis with polyangiitis (Wegener); levamisole; p-ANCA; perinuclear antineutrophil cytoplasmic antibody; purpura; vasculitis; vasculopathy