Symptoms of Scabies that persist for more than 2 weeks after treatment can be due to a various reasons, including:
- Incorrect Diagnosis – Many medicine responses can mimic signs and symptoms of scabies causing skin rash and itching. To diagnose the scabies, it should be confirmed by a skin scraping test, which includes observing the mite, eggs, or mite feces under a microscope. If you sleep with your spouse in the same bed and have not re-infested, and even not retreated yourself for at least 30 days, it is unlikely that your spouse has scabies.
- Reinfestation with scabies can take place from a family member or other infested person if the patient and their contacts are not treated at the same time. Hence, infested person and their contacts must be treated on time to prevent reinfestation.
- Treatment Failure Caused By Resistance To Medication, or by faulty application of topical scabicides can also be a possible reason. No new burrows should appear 24-48 hours after effective treatment.
- Treatment Failure of crusted scabies due to the poor diffusion of scabicides into thick skin containing large numbers of scabies mites. Hence, repeated treatment with a combination of topical and oral medication may be necessary to treat crusted scabies completely.
- Reinfestation From Belongings Of The Affected such as clothing, bedding, or towels that were not properly washed or dry-cleaned. Potentially contaminated items should be machine washed in hot water and dried using the hot temperature cycle, dry-cleaned, or removed from skin contact for at least 72 hours. The house should be vacuumed twice or thrice a week.
- An allergic skin rash (dermatitis);
- Exposure to household mites causing symptoms to persist because of cross-reactivity between mite antigens.
If itching continues more than 2-4 weeks or if new rash continue to appear, seek the advice of a physician. Retreatment with the same or a different scabicide may be necessary.
