Three or four weeks ago, this 56-year-old man noticed asymptomatic lesions on his hands and feet. He says he’s never had anything like them before. He denies taking any new medications and claims to “feel fine,” with no fever, joint pain, or malaise.
EXAMINATION
Numerous round macules and papules are seen on the patient’s palms and soles, many of which have scaly peripheral margins. Most are brownish-red, and they are especially dense on the periphery of the feet.
Looking elsewhere, similar lesions are noted on the penile corona and glans. There is a faint but definite morbiliform, blanchable pink rash covering most of the patient’s trunk, taking on a “shawl” distribution across the shoulders.
These findings prompt a more directed and thorough history, which reveals that the patient is exclusively homosexual and recently engaged in high-risk sexual activity. He denies being HIV-positive, though he admits he hasn’t been tested for several years.
At this point, the patient admits to consulting a urologist two weeks ago. However, he came away from that visit with an assurance that serious disease was “unlikely.”
Accordingly, laboratory tests, including a rapid plasma reagin (RPR), are obtained. The RPR results are positive (1:64). The case is reported to the county health department.
DISCUSSION
It’s been said (by me and others) that half the job of any clinician is staying awake, in advance of the inevitable appearance of serious disease. These diseases are out there but don’t always appear the way they do in the textbooks. “Monroe’s rule #4” says the more serious the skin disease, the less likely it is to be diagnosed in a timely fashion.
It would be hard to imagine a more classic example of secondary syphilis than was seen in this case, occurring in a patient so obviously at risk. But it’s only “obvious” if you’re ready and aware of how syphilis manifests. It also helps if you understand how common it is and who’s likely to get it.
This patient’s primary care provider didn’t recognize the condition and referred the patient to a provider whose specialty is surgical diseases of the urogenital system. I mean no disrespect to urologists (or to urology PAs/NPs), but there’s no particular reason they would know what this was. It’s analogous to the referral of patients to podiatry for a rash or other lesion on the foot. Being a surgical expert on the structural maladies of the foot and ankle in no way imparts expertise in skin diseases of the same areas.
The point is: Skin diseases belong with the experts in skin disease (ie, dermatology providers). They are uniquely qualified, not only in terms of recognizing what is being seen, but in being able to see those findings in the context of other physical and historical data. This case is the perfect example.
Here’s the thought process that occurred in this case: Rashes of the feet and palms are unusual, though far from unknown. But when the rash is composed of round, slightly scaly lesions concentrated on the peripheral feet and hands, the differential narrows significantly. Pointed questions regarding sexual history become necessary. Homosexuality, by itself, is not a risk factor, but engaging in high-risk behaviors performed with exclusively homosexual partners is. These facts, combined with the discovery of the widespread truncal rash, mandated specific blood tests; once those tests confirmed the suspected diagnosis, the law mandated reporting of the case to the health department.
Representatives of said entity will likely confirm the diagnosis with more specific testing, treat the patient (probably with penicillin injection), then take a detailed history of sexual exposure in order to stop the spread of the disease in the community. Physically, this patient will be fine. But, as one might imagine, more fallout can be expected in terms of accusations and denials.
Other items in the differential for such rashes include: lichen planus, psoriasis, and erythema multiforme. A biopsy would have been necessary had the tests for syphilis been negative.
TAKE-HOME LEARNING POINTS
• Palmar and plantar rashes are unusual and should prompt the examiner to expand the history and physical.
• Secondary syphilis, though uncommon, is far from rare, especially among gay men engaging in high-risk sexual behavior.
• It’s common for the patient to deny the appearance of the chancre of primary syphilis, and such a lesion would be long gone by the time those of secondary syphilis manifest.
• Conditions involving the skin should be seen by a dermatology provider, regardless of location. This includes diseases of the skin, hair, nails, oral mucosa, genitals, feet, or palms. One potential exception is the eye itself, though most diseases “of the eye” are, in reality, diseases of the periocular skin—and belong with a dermatology provider.