Confirm exposure to M pneumoniae
Testing with the purpose of ruling in MPAM is directed toward proving that the patient has been exposed to M pneumoniae. (Of note: M pneumoniae cannot be detected via routine commercial blood cultures.)
Serologic testing for elevated IgM antibodies to Mycoplasma is the most specific method. Various studies have found it to be positive in 100% of cases, but detection may be delayed for a couple of weeks while the body develops the requisite antibodies.4
Respiratory PCR for Mycoplasma is rapid and usually appropriately positive, but may be negative in cases where the patient has spontaneously cleared the infection or has been exposed to antibiotics before development of the eruption.4 An infiltrate on chest imaging is supportive of the diagnosis.
Skin biopsy will demonstrate either mucositis and necrosis of keratinocytes or EM-like necrosis, but does not suggest an etiology.
Strikingly different paths of care
Distinguishing between SJS/TEN and EM major (including MPAM) is crucial to guiding management. Patients with SJS/TEN need critical care, particularly of their eyes and genitourinary and respiratory systems. Specialist consultation is often required.
For EM major, patients require supportive care along with ongoing assurances that the eruption has a benign prognosis. Hospital admission is not mandatory as long as adequate supportive care and symptom control can be provided on an outpatient basis. Early consultation with Ophthalmology, Oral Medicine, and Urology may also be key.
Keep in mind that patients may have severe stomatitis and pain that alter their ability to eat and perform normal activities. Thus, managing pain and ensuring adequate nutrition are crucial for successful support. While antibiotics treat active Mycoplasma infection, there is no clear evidence that antibiotics alter the course of the eruption, which is also consistent with the hypothesized pathogenesis.3,4
While there is no clear statistical evidence that systemic immune suppression alters the disease course, a large proportion (31%) of patients in a recent systematic review of MPAM were treated with corticosteroids, and a smaller, but noteworthy, percentage (9%) were treated with intravenous immunoglobulins (IVIG).4 There are reports of severe stomatitis that didn’t improve with supportive care, but that showed dramatic improvement with IVIG treatment.6,7
Our patient had difficulty controlling secretions and managing the painful mucositis of his mouth; he was initially unable to tolerate solid foods. Topical lidocaine solution for his mucositis caused burning and more discomfort, but acetaminophen-hydrocodone 300 mg-5 mg every 6 hours did relieve his pain. Wound care with a bland emollient and the application of non-stick dressings to his lips at night also helped to relieve some of the pain.
Because the patient’s oropharyngeal swelling made it hard for him to swallow, he received oral prednisone 0.5 mg/kg/d, which provided him with relief within 24 hours. The acute inflammation and eruption also subsided within 48 hours and the patient was discharged after 5 days of being hospitalized. He continued to recover as an outpatient, seeing his primary care physician within 2 weeks for final nutrition and wound care support. Two weeks after that, he had a dermatology appointment, and all of his lesions had re-epithelialized.
CORRESPONDENCE
Sahand Rahnama-Moghadam, MD, MS, University of Texas Health Science Center at San Antonio, 7323 Snowden Road, Apt. 1205, San Antonio, TX 78240; sahandazeez@gmail.com.