Reading-Day Yield and Reaction Kinetics of 49 Patch-Test Units in Allergic Contact Cheilitis: An Observational Analytic Case Study in Surakarta

Abstract

Background: Allergic contact cheilitis is a delayed-type hypersensitivity reaction of the vermilion provoked by lip-care and cosmetic products, yet Indonesian data are absent and reading schedules are often truncated.

Objective: To quantify the diagnostic yield each reading day adds, and to describe the reaction kinetics, inter-reading agreement and product-class coherence of the panel.

Methods: An observational analytic case study of a 23-year-old Indonesian woman with seven years of pruritic, dry, fissured lips. The unit of analysis was the patch-test chamber: 49 units, 14 baseline-series allergens and 35 of her own products, graded on the ICDRG scale at 48, 72 and 96 hours (147 observations). Each reading strategy was benchmarked against the union of all three readings, using Fisher’s exact and McNemar tests and weighted kappa.

Results: Seventeen units (34.7%, 95% CI 22.9–48.7%) reached a definite positive. A 48 + 72-hour schedule recovered 13 of 17 (76.5%), missing two petrolatum preparations and two lip balms that the day-4 reading recovered (4 gains, 0 losses; exact p = 0.125). Six units showed crescendo, eight plateau and six decrescendo kinetics; five of seven doubtful 48-hour reactions became definite by day 4. Weighted agreement fell as the interval widened (κ = 0.881 to 0.725). Reactivity concentrated in lip-applied products (11 of 12 versus 3 of 23; odds ratio 59.0; p < 0.001). Scale cleared by day 15 on pimecrolimus 1% cream with structured avoidance.

Conclusion: Retaining the day-4 reading and testing the patient’s own lip products altered the avoidance advice given. No validated severity or quality-of-life instrument was used.