DISCUSSION
Clearly, the basic problem is head lice (pediculosis capitis), with everything else stemming from it. This can be quite confusing for many reasons, not least of which is that one thinks of head lice as a pediatric problem.
The related issue is bacterial infection secondary to scratching and picking, usually from coagulase-negative staph. Minocycline or trimethoprim/sulfa would have been adequate for treatment but of course would not address the main problem: the lice.
Ironically, one of the other impediments to a correct diagnosis was the severity of this patient’s case. It was, without a doubt, the worst I’ve seen in a 30-year career. The nits were so numerous as to render them almost impossible to see without magnification.
There’s little doubt that his wife had them too, adding to the potential for others (eg, grandchildren) around them to be infested as well. Furthermore, this represented a source for re-infestation despite treatment efforts.
Luckily, neither the organisms nor the nits remain viable for long off the body, which means they cannot reside and replicate on inanimate objects. Nonhumans cannot give or get human head lice. Given the organism’s need for warmth and aversion to light, there’s little chance for involvement in areas other than the scalp.
Both the patient and his wife were treated with oral and topical ivermectin. The topical form is applied once to a damp scalp, left on for 10 minutes, then rinsed out. It not only kills the adult organisms but also appears to render the nits nonviable—potentially obviating the necessity of using a nit comb.
The oral ivermectin (150 µg/kg ) was prescribed as follows: four 3-mg tablets now and another four tablets in 10 days to kill any remaining adults. Oral ivermectin is usually not necessary in the treatment of head lice and was only used in this case because of the severity.
Since their cases were so severe, I also advised them both to consider shaving their heads first to facilitate effective treatment. Again, this step is seldom necessary except in the most extreme cases. However, it also facilitated management of their secondary pyoderma, which was treated with trimethoprim/sulfa (double strength, bid for a week).
Since the itching caused by head lice is essentially an allergic reaction to the organism’s protein, that symptom may persist for some time, albeit with gradually diminishing intensity.
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