The case for patch test readings beyond day 2: Notes from the lost and found department

Robert L. Rietschel, Robert M. Adams, Howard I. Maibach, Frances J. Storrs, Lawrence E. Rosenthal

Research output: Contribution to journalArticle

64 Scopus citations


Additional patch test readings taken after 2 days (48 hours) are valuable in distinguishing false-positive reactions, which may occur up to 22% of the time. Second readings taken on days 3 through 7 may detect an additional 34% positive reactivity. Those reactions, both lost (initially positive, later negative) and found (initially negative, later positive) by delayed readings, require clinical correlation for relevance as do the readings that persist at and beyond day 2 (positive at both readings).

Original languageEnglish (US)
Pages (from-to)42-45
Number of pages4
JournalJournal of the American Academy of Dermatology
Issue number1
StatePublished - Jan 1 1988


ASJC Scopus subject areas

  • Dermatology

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