CASE REPORT
A 6-year-old boy with fever was suspected of having Mycoplasma
pneumoniae infection and was prescribed acetaminophen and
clarithromycin in the clinic 7 days before admission. He had no previous
medical or family history. In addition, there was no history of drug
allergy or exposure to suspected drugs before disease onset. At night,
erythema multiform appeared on the patient’s face and trunk. Three days
before admission, he was diagnosed with SJS at a general hospital based
on skin findings. Although he was administered prednisolone (2.0
mg/kg/day), his erythema gradually expanded and developed dyspnea. The
patient was transferred to our hospital for further intensive care.
Upon admission, his vital signs were as follows: body temperature, 37.3
°C; blood pressure, 86/52 mmHg; heart rate, 86 beats/min; respiratory
rate, 36 breaths/min; and oxygen saturation, 90% with
O2 at 8 L/min via an oxygen mask with a reservoir bag.
Retractions appeared immediately below the neck and under the breast.
Subcutaneous emphysema was observed in the cervical and supraclavicular
fossae. Chest examination revealed coarse crackles, decreased breathing
sounds, and bilateral expiratory wheezing. No hyperemia or erosion was
found in the conjunctiva of the eyeball, bloody scabs were found on the
lips, and no redness or erosion was found in the oral cavity. The body
surface area of blisters or erosions was less than 10%, and that of
erythema was 25% (Fig. 1A ). Laboratory examination further
revealed the following findings: white blood cell, 5,800 /µL
(neutrophils 69.6%, lymphocytes 19.3%, and eosinophils 0%); red blood
cells, 482×104 /µL; hemoglobin 13.2 g/dL; platelet,
35.2×104 /µL; total-bilirubin, 7.0 mg/dL; aspartate
aminotransferase, 304 U/L; alanine aminotransferase, 372 U/L; lactate
dehydrogenase, 614 U/L; ferritin, 615 ng/mL; soluble interleukin-2
receptor, 779 U/mL; Krebs von den Lungen 6 (KL-6), 953 U/mL; and
antinuclear antibody titer, 1:40. The drug lymphocyte stimulation test
(DLST) was positive for acetaminophen (H-thymidine, 905 cpm; stimulation
index, 274%) and negative for clarithromycin (H-thymidine, 226 cpm;
stimulation index, 114%). Moreover, the loop-mediated isothermal
amplification (LAMP) assay for M. pneumoniae was negative, and
there was no increase in antibody titer. Chest radiography revealed
subcutaneous emphysema, bilateral mediastinal emphysema, and decreased
permeability in the bilateral middle and lower lung fields (Fig.
1B ).
Based on these findings, we diagnosed severe SJS due to acetaminophen
with mediastinal/subcutaneous emphysema. We also administered high-dose
immunoglobulin (0.5 g/kg/day, for 5 days) and methylprednisolone pulse
therapies (1 g/day for 3 days/week), resulting in an improvement in the
eruption. However, his respiratory failure persisted, and the chest CT
showed a ground-glass-like shadow (Fig. 1C ). We diagnosed
acute respiratory distress
syndrome (ARDS), and cyclosporine (3.0 mg/kg/day) was added to the
treatment regimen on day 9. Artificial respiration with tracheal
intubation was initiated on day 13. Persistent progressive respiratory
failure, veno-venous extracorporeal membrane oxygenation, and
plasmapheresis were introduced on day 44. On day 51, left
hemopneumothorax developed, and thoracoscopic hemostasis and
lung biopsy were performed.
Pathological examination of the pulmonary tissue revealed the diffuse
alveolar injury, confirming the diagnosis of diffuse alveolar damage
(DAD) (Fig. 1D ). Although we performed various
multidisciplinary treatments, his lung lesions showed poor treatment
responsiveness, and he died on day 90.