2 The correct diagnosis dictates correct treatment. This may sound obvious, but in primary care, the emphasis is often on “let’s try this” or “let’s try that,” an understandable approach to a symptomatic patient with an uncertain diagnosis. But by the time he finally gets to dermatology, the patient has tried a whole bag full of prescription and OTC products given for numerous, totally different diagnoses. A better approach might be to expedite an urgent referral to dermatology, when possible.
3 Cutaneous fungal infections (ie, dermatophytosis) are vastly overdiagnosed, especially by novices. If you truly suspect it, ask about a potential source; one doesn’t acquire a fungal infection out of thin air. It must come from a person, animal, or occasionally, the soil. It also helps if the victim has been rendered susceptible by the injudicious use of steroids. Better yet, find the fungus with a microscopic examination (KOH prep) or culture. Finally, remember, not everything round and scaly is fungal (see Figure 2).
4 Remember these ancient words of wisdom regarding skin complaints: (a) A diagnosis is seldom made if not entertained, (b) you won’t entertain it if you’ve never heard of it, (c) you will not see it if you’re not looking for it, and (d) even if you did see it, you would not “see” it because you’re not looking for it. Dermatology is far deeper and wider than most imagine it to be. The trick is to expose yourself to as many different diagnoses as possible, by reading and attending lectures, ahead of the possible sighting. Figures 3 and 4 offer examples of common conditions that are seldom recognized outside dermatology.
5 Skin cancer can present as a rash. Examples abound, such as mammary and extramammary Paget’s disease (Figure 5), mycosis fungoides, metastatic breast cancer (Figure 6), and superficial basal cell carcinoma. A biopsy is usually required to diagnose these, but you wouldn’t think to do that if you’d never heard of the condition.
6 Melanoma doesn’t typically arise from a mole or other pre-existing lesion. Far more often, it arises “de novo,” out of nothing. So, in general, we’re not worried about “moles” (nevi) unless there’s a history of change (see Figure 7).
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