Table 3 Diagnostic criteria for HP in children (modified from [28])
From: Pediatric hypersensitivity pneumonitis: literature update and proposal of a diagnostic algorithm
Suggestive characteristics for HP: 1. Known exposure history to trigger antigen a. positive aerobiological and microbiological environmental investigations b. Sieric specific IgG levels [precipitins, ELISA, ImmunoCAP] 2. Compatible HRCT patternsa 3. Lymphocytosis at BAL (aspecific, not always necessary) 4. Positive inhalation challenge (only in selected patients) • Environmental restatement • Provocation test to the antigen | CONFIDENT HP without biopsy: - Criteria 1 + 2 + 3: Histopathologic confirmation not necessary - Criteria 1 + 2: BAL not necessary in case of clear exposition, typical HRCT, and response after antigen avoidance PROBABLE HPb - Criteria 1 (a or b) + 3; HRCT consistent with other lung diseases - Criteria 2 + 3; no environmental exposure or serologic evidence POSSIBLE HPb - Criteria 1 (a or b); HRCT consistent with other lung diseases; BAL not performed or without lymphocytosis - Criteria 1 (a or b) + 2; BAL without lymphocytosis |