Ectoparasiticides · Ectoparasiticide
When applied to skin, sulfur is slowly reduced to H2S and oxidized to SO2 and pentathionic acid. These, especially the latter, dissolve the cuticle of the itch mite and kill it.
Concurrent use of topical tretinoin and sulfur-containing products can lead to increased skin irritation, dryness, and redness.
Use with caution. If both are necessary, consider alternating application times or reducing the frequency of one or both agents. Monitor for excessive irritation and adjust accordingly.
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Sources: KD Tripathi 7e·Verified: 2026-05-10 · House clinical team