"Doctor," she says, "I have parasites." Insects cover her body, she reports, crawling in and out of her skin, infesting her intestines and appearing in her stool. Sometimes, she says, they are visible in her sputum. They itch. And she scratches, hard. Her hair has been torn out in clumps. "See what I have to do," she says. It is a statement, not a question. She vigorously demonstrates how she scrapes and digs to remove the bugs from her scalp.
They come in a variety of shapes and sizes. She has brought samples in plastic containers, Ziploc bags and Tupperware. She says some are small and red, some white and tube-like, others have round black heads on a stringy body. Many she finds on the ground or the floor of her shower, "after they've fallen off." For months she has showered several times each day in vain attempts to cleanse herself of her tenacious hitchhikers. The containers hold dirt, twigs, pieces of leaves, skin, blood, and water.
"And," she says, finishing her opening monologue, "if one more doctor tells me I'm crazy, I'm going to go postal!"
"How long has this been going on?" At least a year, probably more, she says. Examining her, it looks like it. Her skin is red and patchy, with scabs, scars, and open lesions virtually everywhere she can reach. Areas of skin that are readily accessible for scratching, such as her forearms, neck, scalp, and lower legs, have bloody and crusting sores, some of which appear to have developed mild superficial skin infections. She is anxious to show me her scalp, which has born the worst of her exuberant scratching. Large patches of hair have been torn out, replaced by weeping scabs. Her skin is dry from over-washing, scratching, scraping, and using alcohol swabs in attempts at disinfection. But there are no parasites. No creeping creatures, no mites, no fleas, no bites, no pustules with worms poking their nasty heads out. Her laboratory tests are normal. There are no parasites in her stool.
I know what she has. She has delusional parasitosis. It is a psychiatric condition, unrelated to infectious diseases—except that patients who have it believe they are infested. Antibiotics and antiparasitic drugs have no role, unless the open sores she has created become infected.
Sometimes it is treatable with anti-psychotic medications. But many patients with delusions of parasitic infestations will refuse psychiatric care, believing that this won't help cure their infestation. She, for instance, cannot conceive of the possibility that she is not infested.
So I tell her that I don't know the exact cause of all of her symptoms, but that scratching her sores will not help and that I do not know of any antibiotic that will help either. Perhaps some medicine to reduce her itching. Some skin creams to use when she feels like scratching.
Finally, I broach the subject. "Often situations like yours will improve over time," I say, "though in order to improve you will have to address the psychological stress that having this condition must be putting on you."
"Oh yes," she agrees. Tears form. The stress is tremendous. She is depressed and angry that she can't get better and that no one can tell her what is wrong. Would she be willing to see a psychiatrist that I would recommend? Yes.
I know the diagnosis—but I don't tell her. I will tell her psychiatrist instead.
"Therapeutic privilege," you see. It is the professional privilege that allows physicians to withhold information from a patient when I believe the information might harm the patient.
Though I still wonder whether I did the right thing, I console myself in the fact that she made it relatively easy to withhold her diagnosis. After all, I certainly didn't want her to go postal.