PEMPix is the American Academy of Pediatrics Section on Emergency Medicine’s visual diagnosis competition. It is held annually at the National Conference and Exhibition. This year, all ten finalists will be posted online on and at, one a day with voting opening to AAP Section on Emergency Medicine members thereafter. I hope you enjoy this online-only format, and hope that it will serve to highlight some of the fantastic learning cases that our colleagues submitted this year. It was again very difficult for the panel of judges to select the finalists and I could not have done it without their assistance. As a special treat I’ve included a musical selection form the 1980s as an optional “hint,” and to serve as a soundtrack for your learning.

This PEMPix case was submitted by:

Blake Gruenberg, MD, Pediatric Emergency Medicine Fellow and Daisy Ciener MD, MS, Assistant Professor of Pediatrics from the Vanderbilt University Divison of Pediatric Emergency Medicine

His urine is red and he has a rash


A 13 year old male presented to the Emergency Department with red urine, hives, facial swelling and difficulty breathing. His medical history is significant for an almond allergy, which caused rash but not anaphylaxis. Approximately twelve hours prior to presentation in the Emergency Department he developed facial swelling, hives and difficulty breathing and his mother administered his EpiPen, which lead to prompt resolution in symptoms. They were subsequently seen in their primary care doctor’s office, who observed them briefly and prescribed hydroxyzine and corticosteroids. Later on that day he developed bright red urine, as well as pain in his right lower abdomen localized around a dusky skin lesion as seen below. He was ill appearing overall and in quite a bit of pain.


An area of dusky skin is noted in the right lower abdomen. Image courtesy Blake Gruenberg, MD


Laboratory studies were obtained in the Emergency Department and noteworthy findings included:


  • White blood cell count of 25,000/mm3
  • Hemoglobin 8.5 g/dL and Hematocrit 25%
  • Platelets 23,000/mm3
  • PT 21.6 seconds, PTT 41.9 seconds, and INR 1.9
  • D-Dimer 9089 ng/mL DDU
  • Fibrinogen 269 mg/dl
  • BUN 34 mg/dL, creatinine 1.51 mg/dL, Na 135 mEq/L, K 7.1 mEq/L
  • Total bilirubin 3.2 mg/dl
  • Lactic acid 2.1 mmol/L
  • LDH 3934 U/L
  • Creatinine kinase 302 U/L
  • DAT negative
  • Urinalysis specific gravity of 1.006, 1+ protein, 3+ blood, 0-2 RBC, no nitrates or leukocyte esterase, and Urine myoglobin of 1962 ng/ml


Naturally this ill young man was admitted and his rash continued to progress…


Progression of skin lesions. Images courtesy Blake Gruenberg, MD



What is the diagnosis?

A. Ulceroglandular tularemia

B. Systemic loxoscelism

C. Pyoderma gangrenosum

D. Granulomatosis with polyangitis (Wegners disease)

E. Epinephrine-associated gangrene

B. Systemic Loxoscelism

Systemic loxoscelism is a constitutional illness resulting from the bite of a spider from the genus Loxosceles. In the US this is most commonly from the spider known colloquially as the brown recluse spider, which is endemic to the South and Midwest. The bite of the Loxosceles is usually painless initially. Pain typically develops 2-8hrs after envenomation along with redness at the site of the bite. In rare cases this will progress to a dusky lesion with depressed center which develops into a dry eschar that subsequently ulcerates – this is known as necrotic arachnoidism and was seen in the patient in this case.   The venom of the Loxosceles contains phospholipases D, formerly known as sphingomyelinase, which is thought to cause the majority of damage. It exerts its effects by activating complement and inducing neutrophil chemotaxis and apoptosis of effected cells. Because the bite of Loxosceles is usually initially painless the frequency of systemic loxoscelism after a bite is unknown, but is thought to be rare. When it does occur it manifests as massive hemolysis, hemoglobinuria, acute renal failure, disseminated intravascular coagulation, and rarely death. Treatment of systemic loxoscelism includes supportive care. It is unclear if glucocorticoids or IVIg have any benefit, but can be considered.

Ulceroglandular tularemia is the most common form of tularemia. It is characterized by skin lesions and associated adenopathy. Tularemia itself is caused by infection with Francisella tularensis, an aerobic and fastidious gram-negative bacterium. Human infection occurs following contact with infected vectors – ticks being the most common.   Pyoderma gangrenosum is a rare neutrophilic dermatosis that presents as an inflammatory and ulcerative disorder of the skin. Despite its name it is neither infectious nor gangrenous. It is most commonly found in patients with an underlying disease; inflammatory bowel disease, hematologic diseases, and rheumatic arthridities  are most frequent. It is a diagnosis of exclusion as the clinical, histopathologic, and laboratory findings are nonspecific.   Granulomatosis with polyangitis (Wegener’s granulomatosis) is an antineutrophilic cytoplasmic autoantibody (ANCA) associated vasculitis. Hematuria and cutaneous manifestations, including focal necrosis and ulceration, can be noted on presentation. “Classically” patients also present with a history of both upper and lower respiratory tract symptoms as well (E.g. epistaxis and hemoptysis). A positive ANCA test in the setting of strong clinical suspicion, suggests the diagnosis. However, diagnosis is confirmed by biopsy from a site of active disease.   Epinephrine-associated gangrene is a local manifestation of epinephrine injection most commonly seen after injection of local anesthetics in combination with epinephrine. It is an ischemic process due to the vasoconstrictive properties of epinephrine and is fortunately very rare with accidental EpiPen injections.



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