|
February 2008
By Jeremy Sperling, MD, Osman R. Sayan, MD, and Wallace A. Carter, MD
|
|
|
Problem:
A 25-year-old man presents to your emergency department complaining of a rapidly progressing rash and joint pain. The patient was healthy until five days ago, when he began to feel a burning sensation in his abdomen and vomited once. Later that evening, he developed bilateral elbow pain and swelling followed by a red rash on the distal portions of both lower legs. By the next day, both his wrists were swollen and painful. The patient sought treatment at another hospital, where he received ibuprofen and was released.
The rash is now advancing rapidly up both arms and legs, and his wrists and elbows are becoming increasingly swollen. He denies fever, chills, headache, photophobia, cough, breathing difficulty, chest pain, night sweats, dysuria, hematuria, penile discharge, or rectal bleeding. Outside of Maine, where he works as a restaurant cook, he has traveled to New York and Massachusetts only, and he says he has had no sick contacts. There is nothing of significance, including allergies, in his previous medical and surgical history, and the only medication he has been taking is ibuprofen.
On arrival, his vital signs are: heart rate, 95; blood pressure, 130/85; temperature, 100? F; respirations, 14; and oxygen saturation, 99% on room air. The patient’s HEENT, lung, cardiac, and abdominal exams are unremarkable, and his stool is guaiac-negative. His neck is supple with normal lymph nodes. He has purpuric papules on his lower extremities extending from his dorsal feet to his buttocks. The rash is confluent over his knees and parts of his lower legs. Similar lesions are present on his abdomen, elbows, antecubital fossae, palms, and soles. His hands, wrists, knees, ankles, and elbows are swollen and tender, but no warmth or erythema is noted. Electrolytes, creatinine, platelet count, and coagulation studies are all normal.
What diagnosis are you about to miss?
Click for answer |
| |
| |
 
|
|
Answer:
The differential diagnosis of a patient with a petechial or purpuric rash is quite broad and can include vasculitides, sepsis (for example, meningococcemia), and disseminated intravascular coagulation. Purpuric and petechial rashes are commonly caused by low platelet counts (as in immune thrombocytopenic purpura, drug-induced thrombocytopenia, or thrombotic thrombocytopenic purpura), platelets that are not functioning, or clotting factor defects. This patient, however, has a normal platelet count and normal coagulation studies which narrows the differential diagnosis.
Rocky Mountain spotted fever (RMSF) usually starts with a rash around the ankles and wrists that progresses towards the trunk. Although RMSF is a tick-borne illness, bites are not always reported. As in this case, the rash can appear on the palms and soles and abdominal pain can be present. It should be noted, however, that in RMSF both fever and headache tend to be prominent. Secondary syphilis should always be considered and tested for when rashes present on the palms and soles, although that diagnosis is less likely in this patient given that there is no mucous membrane involvement or lymphadenopathy and he has never had a chancre lesion.
A number of vasculitides can present with a normal platelet count and this type of rash. Hypersensitivity vasculitis can present with purpura or petechiae, arthralgias, and fever. Usually the leading suspect is a new drug regimen or an infection like HIV or hepatitis B or C. Other symptoms may include adenopathy and urticaria. This patient had neither of these symptoms nor any new drug exposures. The results of HIV, hepatitis B, and hepatitis C tests for this patient were not known in the emergency department. Another type of vasculitis that can present with palpable purpura is Churg-Strauss syndrome. In Churg-Strauss, however, pulmonary symptoms predominate and patients usually have a prior asthma history.
Henoch-Schönlein purpura (HSP) is a small-vessel vasculitis generally characterized by purpura, arthritis, abdominal pain, and hematuria. The exact etiology is unknown, but it is much more common in children. While hematuria wasn’t present in this patient, the other three major features were. With HSP, there is a possibility of significant renal impairment, especially in adults. Additionally, it may cause gastrointestinal hemorrhage and abdominal pain, and will occasionally lead to obstruction or intussusception. (The latter complication is rare in adults.)
Although the diagnosis of HSP was highly suspected on clinical grounds, a biopsy was performed because the disease is relatively uncommon in adults. A biopsy of the patient’s lower back showed a moderately severe necrotizing leukocytoclastic vasculitis consistent with HSP. The patient was admitted for observation and did not develop significant renal or gastrointestinal sequelae. Close outpatient follow-up was arranged.
|
|
Dr. Sperling is an assistant residency director in emergency medicine at New York-Presbyterian Hospital and an assistant professor of medicine at Weill Medical College of Cornell University in New York City. Dr. Sayan is an assistant residency director in emergency medicine at New York-Presbyterian Hospital and an assistant clinical professor of medicine at Columbia University College of Physicians and Surgeons in New York City. Dr. Carter, editor of “Would You Miss This Diagnosis?”, is program director for the emergency medicine residency at New York-Presbyterian Hospital, associate professor of emergency medicine in medicine at Weill Medical College of Cornell University, and an associate professor of clinical medicine at Columbia University College of Physicians and Surgeons.
Emerg Med 40(2):35-36, 2008 |
|
