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 i na good hotel. Without warning, one morning t heystarted the pest control, spraying the rooms with DDT. The substance w asco nfirmed by our group leader. Our clothing and belongings stayed in the rooms, and we were told to stay out for three to four hours. The fumes were thick and heavy. Afterward no cleaning was done, no bedding was changed, a ndwehadto sleep with smelly sheets breathing the fumes.

When I got back home, Is tarted having a feelinglikesome thing was “crawling” on the back of my head. I thought I h ad lice, and I used two over-the-counter 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 definitel y do not have lice. The crawling sensation continues, and it h asmovedfrom the back of my head to the left temple. It’s always in one spot. It started on the ba ck,t he next time, itmovedtotheleft,and now it’ s on the left temple. It can go away for a few days. It started right after the Cuba incident, and I have never experienced anything like this before.

Is it possibl ethat this w as caused by the DDT or the lice treatment t hatI used? Whatsh ould I do to get rid of it? — R.M.

Answer: 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 trea tl ice (which I don’t think you ever had). Permethrin is well-known to cause nerve symptoms, especiall y itching and a pins-and-needles sensation. I wonder whether, with two lice treatments

Ion top of the exp osurein the hotel, you developed toxicity from permethrin. However, I could not find any evidence of longterm damage from permethrin. There are no case reports of people having symptoms so long after exposure. So, while it is possible, th ats eems unlikely.

Thefactt ha titmoves around a bit on the scalp also suggests no permanent nerve damage, as d oest h efactth at i tca n go away for a few days.

Idon ’t know what’s causing your symptoms, but many times, worry rela tedt o illness, infection or infestation can lead to very real symptoms. It is possibl ethatyouare so worried about having been damaged by the exp osurethats ome part of the physical symptoms is due to being so (understandably) nervous about it. I certainly recommend t hatyouvi sit a dermatologist to be sure there is not some skin condition you can’t see that is unrelated to the exposure.