Unusual reaction to an influenza vaccination Primary Care Conference Clinical Case Presentation Rebecca Byers MD April 12, 2006

Clinical Scenario Patient is a 50 year old woman who presented to clinic Feb with a nontender, indurated-feeling left triceps muscle. HPI - no recent illness. Had flu vaccine in left deltoid Jan PMH - hyperlipidemia, chronic rhinitis. Meds - aspirin, Niaspan, Ortho Tri-cyclen, Allegra, Zocor.

Exam Afeb. VSS. Left upper extremity - no skin changes. 4 to 5 cm by 3 cm indurated area over the triceps. Nontender. Skin exam o/w unremarkable. No LAD anywhere. Lungs, Cardiac, Abdomen - all normal.

Consults/Tests Ordered MRI and scheduled appt for pt in Oncology, with concern of sarcoma. MRI - lesion limited to subcutaneous fat and did not invade muscle. Referred to Dermatology. Subcutaneous biopsy - Granulomatous Dermatitis, Sarcoidal Type.

Chest CT Bilateral hilar adenopathy and right paratracheal adenopathy with no evidence of significant lung parenchymal involvement. No prior chest films available.

PFTs FEV (132% predicted) FVC 4.49 (129% predicted) Ratio 0.78 DLCO 98%

Labs CBC - WBC 6.3 with nl diff, hct 44, plts 294,000. Creat 0.9. ACE level 38. CK 23. ALT 32.

Further consults Ophtho - No evidence of ocular sarcoid. Pulmonary - Confirmed diagnosis of Stage I pulmonary sarcoid with extrapulmonary involvement. Discussed possible treatment (steroids, hydroxychloroquine); decided on watchful waiting, with recommendation to return in 6 months for followup.

Sarcoidosis Systemic granulomatous disease that primarily affects the pulmonary and lymphatic systems. Diagnosis is established when clinico- radiological findings are supported by histological evidence of noncaseating epithelioid cell granulomas.

Etiology The exact cause(s) of sarcoid are unknown, but there are 3 different lines of evidence supporting the theory that sarcoid occurs in genetically susceptible hosts when exposed to specific environmental agents.

Conclusion Plausible that the influenza vaccine, administered subcutaneously, was the environmental antigen that triggered the patient’s local granulomatous response.

Objectives To illustrate a clinical case in which the patient identified the most likely causative event for her subsequent diagnosis. To describe a clinical case in need of evidence-based criteria to help determine cause and future treatment decisions. No financial disclosures.

References ATS guidelines: Statement on sarcoidosis. The American Thoracic Society, Am J Respir Crit Care Med 1999; 160:736. Martinetti, M, Tinelli, D, Kolek, V, et al. “The sarcoidosis map”: A joint survey of clinical and immunogenetic findings in two European countries. Am J Respir Crit Care Med 1995; 152:557.