Phantom itch is an international mystery

Dear Dr. Roach: Two years ago, I spent a month in Havana, Cuba, to study Spanish. We were staying in a good hotel. Without warning, one morning they started pest control by spraying the rooms with DDT. The substance was confirmed by our group leader. Our clothing and belongings stayed in the rooms, and we were told to stay out for three to four hours. When I got back home, I started having a feeling like something was “crawling” on the back of my head. I thought I had lice, and I used two over-thecounter treatments (permethrin) to get rid of them. After that I went to a lice clinic to make sure I didn’t have them. The clinic confirmed I definitely do not have lice. The crawling sensation continues, and it has moved from the back of my head to the left temple. It’s always in one spot. It started on the back, the next time, it moved to the left, and now it’s on the left temple. It can go away for a few days. It started right after the Cuba incident. Is it possible that this was caused by the DDT or the lice treatment that I used? What should I do to get rid of it? — R.M.

DDT was banned in Cuba in 1970, and although some reporters suspect the continued use of DDT despite that, there is no convincing evidence that this is the case.

The spray that pest control used almost certainly was permethrin, the same substance you used to treat lice, which is known to cause nerve symptoms, especially itching and a pins-and-needles sensation. I wonder if you developed toxicity from it.

The fact that the sensation moves around on the scalp also suggests no permanent nerve damage, as does the fact that it can go away for a few days.

I recommend that you visit a dermatologist to be sure there is not some skin condition you can’t see that is unrelated to the exposure.

Write to Dr. Roach at ToYourGoodHealth @med.cornell.edu.