A 23-year-old woman presents to your acute care clinic with a complaint of fever, sore throat, and malaise of sudden onset. Her prior medical history is significant for schizophrenia. Her vitals signs are:
BP 116/80, HR 112, RR 26, Temp 100.6 degrees Fahrenheit. On physical examination, her oral cavity features painful aphthous ulcers as well as swollen gums. Initial laboratory testing includes a CBC which returns with the following results:
· Leukocyte count 800/mm3
· Hgb 12.1 g/dL
· HCT 37.0%
· Platelet count 212 × 109/L
· Differential:
· Neutrophils, segmented 52%
· Neutrophils, bands 3%
· Lymphocytes 35%
· Monocytes 7%
· Eosinophils 3%
· Basophils 0%
Which of the following best describes the expected course of the patient's condition?
- The condition is usually self-limiting and requires no intervention.
- Use of G-CSF has been shown to speed recovery.
- Dose reduction of the offending agent often leads to resolution of symptoms.
- If discovered earlier, discontinuation of the offending agent would have prevented progression of the condition to its current severity.
- Tardive dyskinesia usually develops as a late finding.
Answer(s): B
Explanation:
This patient's presentation is consistent with agranulocytosis, which is defined by an absolute neutrophil count (ANC) of fewer than 500/mm3. ANC is defined as the percentage of the WBC count that is accounted for by segmented neutrophils and bands. In the case of this patient, the ANC is 55% of the WBC count or 440/mm3. Individuals with agranulocytosis commonly experience a sudden onset of malaise, fever, chills, and pharyngitis. They may also develop painful aphthous ulcers affecting the oropharyngeal mucosa. Suppression of the bone marrow, including agranulocytosis, is associated with the use of clozapine. The incidence approaches 1% within several months of treatment, independent of dose. Patients on clozapine should be monitored closely with weekly measurement of the CBC. Mild leukocytosis and other blood dyscrasias occur much less frequently with other antipsychotic drugs.Usually, there is a prodrome of several weeks duration in which the WBC count gradually declines. Decreasing the dose or discontinuing the offending agent does not always prevent progression to full blown agranulocytosis. Patients with druginduced neutropenia recover more quickly with the assistance of granulocyte colonystimulating factor (G-CSF). Additionally, individuals suffering from agranulocytosis frequently develop infections which require the use of antibiotic therapy. In these cases, further supportive and symptomatic care may be necessary depending on the severity of infection. Delaying or withholding intervention is inappropriate. Tardive dyskinesia is an adverse effect related to use of antipsychotic medications; it is not inherently related to agranulocytosis.