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Heavy Metal Index

Methylisothiazolinone: A Case of Perianal Dermatitis Caused by Wet Wipes and Review of an Emerging Pediatric Allergen

This case report describes a 9-year-old boy with five weeks of pruritic perianal dermatitis that had not responded to a barrier cream, an antifungal cream, or an antibiotic.

This case report describes a 9-year-old boy with five weeks of pruritic perianal dermatitis that had not responded to a barrier cream, an antifungal cream, or an antibiotic. The eruption matched the area of contact with wet wipes. A commercial patch test gave a 2+ reaction to the methylchloroisothiazolinone/methylisothiazolinone mix, and methylisothiazolinone was listed on the wipes he brought to clinic. The dermatitis cleared after the wipes were stopped. No heavy-metal concentration is reported. The paper does not assay the wipes.

Key numbers

This source does not report a heavy-metal concentration, a metal release value, or a metal limit of its own.

Methods (brief)

Single-patient case. Patch testing used a commercial thin-layer rapid use epicutaneous test. Avoidance counseling used the product ingredient list. The family did not reintroduce the wipes for a confirmatory use test. Table 1 is a sample of other products reported elsewhere to contain methylisothiazolinone, not measurements from this case.

Evidence fitness

A single pediatric case in which perianal dermatitis cleared after stopping wet wipes that listed methylisothiazolinone, following a 2+ patch test to the MCI/MI mix.

They do not support Any heavy-metal concentration; A measured methylisothiazolinone or methylchloroisothiazolinone concentration in the wipes. Presence was taken from the ingredient list; A population sensitization rate. The statement that testing with the MCI/MI mix can miss approximately 40% of MI allergy is cited from another paper, not measured here.

Limitations

One patient. Relevance was judged probable because the family declined to rechallenge. Patch testing used the MCI/MI mix rather than methylisothiazolinone alone. Product identity rests on the label, not on a laboratory concentration.

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