Comprehensive Pediatrics Glossary

Z

Zellweger Syndrome (Cerebrohepatorenal Syndrome)

  • Definition: Rare autosomal recessive peroxisomal biogenesis disorder resulting in defective peroxisomes and accumulation of very long-chain fatty acids (VLCFA).

  • Clinical Features: Hypotonia (“floppy infant”), distinctive facial features (high forehead, flat occiput, broad nasal bridge), seizures, hepatomegaly, developmental delay, visual/hearing impairment.

  • Investigations: Plasma VLCFA measurement, liver function tests, brain MRI (white matter abnormalities), genetic testing for PEX gene mutations.

  • Management: Supportive care: nutrition, physical therapy, seizure management, ophthalmologic care. No curative treatment exists.

  • Complications: Progressive neurological deterioration, liver failure, early mortality (usually within first year).

Zika Virus Infection (Pediatric)

  • Definition: Mosquito-borne flavivirus infection with congenital and postnatal manifestations in children.

  • Epidemiology: Transmitted by Aedes mosquitoes; vertical transmission can cause congenital Zika syndrome.

  • Clinical Features: Fever, rash, conjunctivitis, arthralgia, microcephaly, developmental delay in congenital cases.

  • Investigations: RT-PCR from serum, urine, or amniotic fluid; serology for IgM/IgG antibodies.

  • Management: Supportive care: hydration, antipyretics, developmental therapy for congenital cases, prevention through vector control.

  • Complications: Congenital microcephaly, neurodevelopmental delay, Guillain-Barré syndrome (rare in postnatal infection).

Zollinger-Ellison Syndrome (Pediatric)

  • Definition: Rare condition characterized by gastrin-secreting tumors (gastrinomas) leading to gastric acid hypersecretion and peptic ulcer disease.

  • Clinical Features: Abdominal pain, vomiting, diarrhea, gastrointestinal bleeding, failure to thrive.

  • Investigations: Elevated serum gastrin levels, secretin stimulation test, endoscopy (peptic ulcers), imaging (CT/MRI, somatostatin receptor scintigraphy).

  • Management: Proton pump inhibitors to control acid, surgical resection of gastrinomas, management of complications.

  • Complications: Recurrent ulcers, GI bleeding, metastasis of gastrinomas.

Zinc Deficiency

  • Definition: Insufficient zinc intake or absorption causing growth retardation, immune dysfunction, and skin/mucosal lesions.

  • Epidemiology: More common in low-income regions; may result from malnutrition or malabsorption.

  • Clinical Features: Growth retardation, delayed wound healing, alopecia, dermatitis (acrodermatitis enteropathica-like), impaired taste, recurrent infections.

  • Investigations: Serum zinc levels (low), dietary history, evaluation for malabsorption.

  • Management: Oral zinc supplementation, correction of dietary deficiency, treatment of underlying malabsorption.

  • Complications: Severe growth failure, increased infection susceptibility, delayed sexual maturation.

Zygomycosis (Mucormycosis, Pediatric)

  • Definition: Rare but serious fungal infection caused by Mucorales species, often affecting immunocompromised children.

  • Clinical Features: Rhinocerebral: nasal congestion, facial swelling, black eschar on palate/nose; pulmonary: fever, cough, respiratory distress; gastrointestinal: abdominal pain, necrosis.

  • Investigations: Direct microscopy and culture of tissue biopsy, imaging (CT/MRI for extent), histopathology showing broad, aseptate hyphae.

  • Management: Urgent surgical debridement, intravenous amphotericin B, supportive care, correction of underlying immunodeficiency.

  • Complications: Tissue necrosis, orbital or cerebral invasion, multi-organ failure, high mortality if untreated.

Zollinger-Ellison Syndrome – Pediatric Variant

(Optional detailed pediatric-specific note)

  • Pediatric cases often present with multiple recurrent ulcers rather than classical adult patterns. Screening for multiple endocrine neoplasia type 1 (MEN1) is advised in children with gastrinomas.

 

Bookmark