[Question #7194] Pubic lice/crabs

7 months ago

My fiancé found a few lice on the upper line of his pubic hair and many more on the back sides of his legs. No white eggs- only firm, dark dots near the base of some leg hairs. He used lice shampoo and still had itching (even his scalp itched in one spot) and a few red areas along the top line of his pubic hair. He also had something tiny embedded in his armpit that hurt when he pulled on it. I had no symptoms, though I too used the shampoo. I then had std testing (all negative) and was told it is extremely unlikely to get 'crabs' in any way other than sex.

My fiancé believed he may have gotten this from performing dental work in a home for older people in a very poor setting (which he did only a few days before finding these lice), or from laying on gym mats (which are used daily by random people) while wearing shorts. The ones on the back sides of his legs itched the most, though the only 'crab-like' ones were near the top line of his pubic hair (none further down in the pelvic region). He also said the 'crab-like' ones were digging into his skin, that he had to pull them out. I had ruled out ticks, based on appearance (hook hands), though oddly I had a tick in my shoulder only a few days prior. I know it ultimately comes down to my trust in him. What is the likelihood he may have gotten this from a gym mat or by performing dental work on unclean people, or in any other way? He does not share bedding, towels or clothing with anyone else, to my knowledge.

H. Hunter Handsfield, MD

7 months ago

Welcome to the forum. Thanks for your confidence in our services.

There are some peculiar aspects in your description. Pubic lice (Phthirus pubis) ("crabs") rarely infest sites other than the pubic area and sometimes eyelashes, not frequently the scalp or legs. However, head and body lice (P. captitis) could affect these locations. In addition, "brown spots" aren't necessarily lice, and as you seem to know, usually nits (white eggs) are readily apparent. Are you certain he has lice? If in doubt, remove one of the brown spots and look with a magnifying glass.

Assuming both the diagnosis and exposure history are correct, all the exposures you describe are very plausible for head/body lice; and the gym mat is plausible for pubic lice. You obviously understand the basics about pubic lice, but they are better thought of as sexually transmissible but not necessarily sexually transmitted. That is, sex itself isn't necessary for transmission, and nonsexual contact with infested persons' clothing, bed sheets, etc undoubtedly explain many cases. And gym mats are plausible.

If it turns out to be head/body lice (or no lice at all), for sure you should not be at all concerned about any sexual issues. And even if pubic lice, if you otherwise have no reason to suspect your fiance's fidelity, this shouldn't change anything.

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

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7 months ago

Thank you, Dr. Handsfield. I couldn't fit all of the details into my post, but I am certain they were pubic lice due to the physical characteristics. They were more round in shape, with two longer arms and 'pincher' hands. When he pulled one off, a hair came with it and I saw it clinging to the hair. These were only found in his pubic hair. There was something going on with his legs as well and that is what makes the whole situation odd. Your information is helpful. I did do some internet "research" but I know it is important to speak with a doctor directly.

I am still wondering about the likelihood of the gym mat. My understanding is that pubic lice do not move well on smooth surfaces and prefer to be attached to a human body at all times, making direct bodily contact the primary method of transmission. Is this true? The gym mats are usually hung up before the next person uses them. I hadn't mentioned that before either. Is it possible he could have gotten them from working in the home for the elderly? If not sexually transmitted, what are the other ways one might get pubic lice? They don't jump do they? I really don't think he has shared clothing, bedding or towels and that is what makes this so difficult for me to understand. Of course I won't ask for relationship advice. I am just trying to make some sense of an uncomfortable situation.

H. Hunter Handsfield, MD

7 months ago

OK, pubic lice. Still, I would never take crab lice infestation alone as clear evidence of sexual infidelity. And no, they don't jump. Contact with elderly or disabled folks in an adult family home, nursing home, etc? Maybe. Among people with crabs, there are many who don't give a history that would suggest sexual acquistion -- certainly higher frequency and thus a different level of evidence than, say, newly diagnosed chlamydia or gonorrhea. Some cases are just unexplained. That said, common practice and routine recommendations (e.g. from CDC) are thart persons with pubic lice infestation should be tested for other STDs, just to be on the safe side. But my basic advice is unchanged: if you have no other reason to suspect your fiance has had other partners, this alone doesn't necessarily change anything.

I'm glad you're not asking (primarily) for relationship advice. But given your concerns, maybe it's time for a senstive, mutually caring heart to heart discussion. In any case, you know him and I don't: you're the only one in a position to judge the possibilities and likelihoods.

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