1. What essential question remains to be asked in order to make the diagnosis?
2. What is the tentative diagnosis?
3. Can you list at least three differential diagnoses?
4. What features of this condition separate it from other conditions in the differential diagnosis?
5. What is the suitable treatment of this rash?
When A Patient Presents With A Lower Extremity Rash
Podiatric physicians are often presented with dilemmas when diagnosing various dermatological conditions as these conditions may have overlapping symptoms. An accurate diagnosis is dependent on the patient history, physical examination and asking key questions to elicit telling answers from the patient. Accordingly, we have launched a new bimonthly column, “Dermatology Diagnosis,” that will test one’s skills in diagnosing dermatological conditions. Without further delay, let us consider the first case. A 26-year-old male presents with a four-day history of red, itchy bumps on his lower legs. He says he woke up four days before with itching on both lower legs and noticed small red bumps beginning below both of his knees and progressing down toward his feet. After approximately 24 hours, the patient noticed that the condition started to itch more and appeared to get worse. During the history portion of the visit, the patient says he had no idea how the rash started and had no previous history of a similar rash anywhere on his body. He reported that he was otherwise in good health but recently had systemic symptoms of fatigue, joint pain, muscle aches and a mild headache, which he first noted two days after the rash appeared. The patient has no history of allergy to any medications, foods or other substances, and is not taking any medications or vitamins at this time. Furthermore, the patient maintains he had not started to use any new cleaning products, bath soaps, laundry detergents or topical preparations of any kind prior to this problem. He has not gone camping or hiking in the past month, and has not gone out of the state in the last two months. The patient says he checked his bed carefully for any bugs and found none. None of his roommates has a similar problem.
What Did The Examination Reveal?
The physical examination shows an array of small (3 to 8 mm) erythematous, pruritic, follicular papular eruptions, many with apparent pustules, confined to the lower legs. There are a few small areas of urticaria and a few small nodular lesions on the legs. There are no lesions on the hands, arms or feet. Upon careful questioning of the patient, he reveals that he has a few similar lesions around the groin area. Some of the larger lesions are tender to direct palpation. There is no increase in skin temperature and no edema. The remaining examination is negative for elevated oral temperature or other signs or symptoms. There are no other obvious dermatological findings other than those noted from the initial examination.