HPI: 56 yo male presents to the clinic with a new onset rash (“ronchas” as he described, which translates to “hives”) that appeared abruptly and without any impending event within the past day. Since its initial appearance which started in his abdomen, it has since spread all over his thorax and upper back, as well as to both arms. He also notes that it has begun to itch, and becomes even worse when he scratches. He denies any recent shortness of breath or difficulty breathing, and denies any other associated symptoms including fevers, nausea/vomiting, chills/sweats, or any pain. He has never had this problem in the past, and denies any previous food allergies. He does not note any recent eliciting event, or any particular food that he believes may have caused this reaction. He has not taken any recent medicine or treatment for his symptoms, including aspirin, NSAIDs, antibiotics, herbs, and supplements.
PMHx, PSHx, FHx, SHx: No significant past medical history. No recent environmental of food exposure (including insects) of note by the patient. No significant family history.
Physical Exam:
Vital Signs: Within normal limits
Gen: No acute distress
HEENT: Airway is patent/clear, no laryngeal involvement or swelling around the neck/throat. No evidence of angioedema.
Lungs/Heart: Clear, regular rate and rhythm.
Skin: As shown below, erythemetous, circumferential rash that involves the entire thorax and abdomen, upper back, and both forearms. The rash is not palpable/elevated, but does blanch when pressed. There is no evidence of dermographism.
Blanching skin rash located on the abdomen and thorax of the patient
Same rash, also located on the forearms.
Brief Differential Diagnosis:
-Urticaria (see further classification below)
-Drug Eruption
-Serum Sickness
-Mastocytosis (…zebra)
Diagnostic Tests: None ordered.
Treatment Plan: Although this patient did not have the classic skin appearance of wheals, we diagnosed him with idiopathic urticaria, based on his history and physical. The lesions were not palpable or raised, but did blanch upon pressure. We were not able to elicit any precipitating event that may have lead to his symptoms. The problem with urticaria when trying to make a diagnosis is that it is often migratory and transient, which means it does not always present with the classic lesions. It could have also been some other rash or reaction, but we also felt it was urticarial based on its rather acute presentation. As such, we decided to treat the patient for urticaria, and since he never returned to clinic, we hope his symptoms resolved.
Table showing the different classifications of urticaria.
Criteria used to help diagnose urticaria.
Because the patient was not in any respiratory distress, and there was no evidence of angioedema or laryngeal involvement, we treated him symptomatically (epinephrine is the mainstay treatment if there had been an anaphylactic reaction). Most cases of simple urticaria (as in our case) can be treated with H1 antihistamine agents. The only problem with these agents is that they can be sedating. We chose to give cetirizine (zyrtec) because it was available in our formulary. Because of the extensive involvement of the rash around the patient’s body, we also gave him a shot of dexamethasone (glucocorticoid) to help decrease the inflammatory response. Another reason for treating with antihistamines/steroids is that this is a common, effective treatment for other inflammatory reactions as well, such as drug eruptions. I didn’t know at the time of treating our patient, but apparently there is a scoring system called the urticaria activity score (UAS) that is commonly used to assess severity and evaluate the patient’s response to treatment over the next few days.
Scoring system used to evaluate severity of urticarial symptoms and monitor treatment response.