DISCUSSION
Leg skin is prey to an astonishing array of problems; many have to do with increased hydrostatic pressure (eg, venous stasis disease), with the almost complete lack of sebaceous glands (eg, nummular eczema), or with the simple fact of being “in harm’s way.” And there is no law that says a given patient can’t have more than one problem at a time, co-existing and serving to confuse the examiner. Such is the case with this patient.
Her concern about possible blood clots is misplaced but understandable. Deep vein thromboses would not present in multiples, would not be on the surface or scaly, and would almost certainly be painful.
The fixed nature of this patient’s scaly lesions is extremely significant—but only if you know about DSAP, which typically manifests in the third decade of life and slowly worsens. The lesions’ highly palpable and unique scaly border makes them hard to leave alone. This might not be a problem except for the warfarin, which makes otherwise minor trauma visible as purpuric macules. Chronic sun damage tends to accentuate them as well. The positive family history is nicely corroborative and quite common.
The brown macules on the patient’s legs are solar lentigines (sun-caused freckles), which many patients (and even younger providers) erroneously call “age spots.” When these individuals become “aged,” they’ll understand that there is no such thing as an age spot.
This patient could easily have had nummular eczema, but not for 30 years! Those lesions, treated or not, will come and go. But not DSAP, about which many questions remain: If they’re caused by sun exposure, why don’t we see them more often on the face and arms? And why don’t we see them on the sun-damaged skin of older men?
If needed, a biopsy could have been performed. It would have been confirmatory of the diagnosis and effectively would have ruled out the other items in the differential, including wart, squamous cell carcinoma, and actinic or seborrheic keratosis.