Ecthyma gangrenosum due to Pseudomonas aeruginosa sepsis as initial manifestation of X-linked agammaglobulinemia: a case report

Abstract

Background: X-linked agammaglobulinemia (XLA, OMIM#300,300), caused by mutations in the Bruton tyrosine kinase (BTK) gene, is a rare monogenic inheritable immunodeficiency disorder. Ecthyma gangrenosum is a cutaneous lesion caused by Pseudomonas aeruginosa that typically occurs in patients with XLA and other immunodeficiencies.

Case presentation: We report the case of a 20-month-old boy who presented with fever, vomiting, diarrhea, and ecthyma gangrenosum. Blood, stool, and skin lesion culture samples were positive for P. aeruginosa. A diagnosis of XLA was established, and the c.262G > T mutation in exon 4 of BTK was identified with Sanger sequencing. Symptoms improved following treatment with antibiotics and immunoglobulin infusion.

Conclusions: Primary immunodeficiency (i.e., XLA) should be suspected in male infants with P. aeruginosa sepsis, highlighting the importance of genetic and immune testing in these patients.

Keywords: Ecthyma gangrenosum; Pseudomonas aeruginosa; X-linked agammaglobulinemia; male infants.

Fig. 1

General appearance of the patient showing multiple purple necrotic lesions. (A) Day 1, ICU: Initial appearance of the abdominal lesions of ecthyma gangrenosum (a). (B) Day 2, ICU: The black central eschar in the lesion was deep seated and large (a`). (C) Day 1, ICU: Initial appearance of the lesions over the right lower leg (b&c).(D) Day 2, ICU: The erythematous lesions appeared as gangrenous ulcers (b`); The black central eschar was deep seated and large (c`)

Fig. 2

Serial CT and MRI images showing changes in the brain. a Day 19 of admission: Lateralcranial CT showing diffuse brain edema, hypodensity of the brain parenchyma, and subdural effusion in the bilateral frontal area (red arrow). b Day 25 of admission (one day before Ommaya reservoir implantation): Lateral T2-weighted MRI showing enlarged lateral ventricles and hydrops with peripheral white matter edema. c Day 27 of admission (one day after Ommaya reservoir implantation): Lateral cranial CT showing the drainage tube in the anterior horn of the left lateral ventricle. d Day 70 of admission (one day before ventriculoperitoneal shunt): Lateral T2-weighted MRI showing hydrocephalus in the ventricles was not obviously aggravated. e Day 72 of admission (one day after ventriculoperitoneal shunt): Lateral cranial CT showing the drainage tube in the lateral ventricle. e 20 months after discharge: Lateral T2-weighted MRI showing less hydrocephalus and improved interstitial cerebral edema

Fig. 3

Results of Sanger sequencing for blood samples from the patient (upper panel) and parents (bottom panel)

Fig. 4

X-ray and MRI images showing changes around the left elbow. (A) Day 29 of admission: X-ray showing swelling of soft tissue around the left elbow (arrow). (B) Day 47 of admission: Coronal T2-weighted MRI showing patchy hyperintensity in the left humerus and proximal ulna (a) accompanied by soft tissue edema and abscess formation around the elbow joint (b).(C) Day 96 of admission: X-ray showing low-density shadows in the left humerus, suggesting bone destruction (c). Similar less severe changes were observed in the proximal left ulna (d). Soft tissue swelling was reduced