Variegate Porphyria Reported in Girl With Several Underlying Conditions
Ailment is caused by PPOX gene mutation, leading to toxic porphyrin precursor levels
A report described a case of variegate porphyria, a type of acute porphyria, in a 9-year-old girl who had several underlying medical conditions, including a severe form of epilepsy.
The researchers noted that while variegate porphyria is not frequently seen in children, when it is it’s “associated with more severe neuropsychiatric outcomes compared to adult-onset disease.”
The report, “A 9-year-old girl with blisters on the hands and face: An early presentation of variegate porphyria,” was published in Pediatric Dermatology.
Variegate porphyria is caused by mutations in the PPOX gene, which contains instructions for making an enzyme called protoporphyrinogen oxidase which is involved in producing heme, a key molecule required for transporting oxygen in the body.
People with variegate porphyria have a dysfunctional enzyme that leads to porphyrin precursors building up to toxic levels in the body over time. Typical symptoms include blisters on sun-exposed skin areas, abdominal pain, seizures, and muscle weakness.
Most cases have been reported in older children, adolescents, and adults. Here, a research team from Virginia Commonwealth University described the case of a young girl with the condition.
The girl, from El Salvador, was brought to the dermatology clinic due to blistering sores scattered on her face. Her medical history included a premature birth at 29 weeks, developmental delay, and cerebral palsy that affected both arms and both legs. She also had Lennox-Gastaut syndrome, a severe form of epilepsy that was not properly controlled by medication.
Blisters started appearing a year earlier, with the first lesions appearing on her face, particularly where surgical tape had been used in a previous surgery. Her mother said she had been biting her hands more frequently, with more sores developing at multiple sites, including her face and hands. The girl’s feet had become red and swollen and she had chronic vomiting and constipation.
Prior interventions included immobilizing her arms to reduce friction and scratching and using topical medications. No improvements were seen and the cause of her lesions remained unknown, however.
A physical examination revealed several scars across her face and on the back of her hands, the latter accompanied by tiny white bumps called milia.
A complete blood count showed slightly elevated levels of hemoglobin, the protein in red blood cells responsible for oxygen transport, and hematocrit, the proportion of red blood cells in the total blood volume, along with certain liver enzymes.
Tissue analyses of two blisters showed signs of inflammation. Also, she had elevated levels of porphyrins in her blood and urine. Genetic testing revealed a mutation in the PPOX gene, confirming variegate porphyria.
The girl also had another mutation in the FECH gene, linked to erythropoietic protoporphyria. This gene carries instructions to make an enzyme called ferrochelatase that’s also involved in heme production. However, since the mutation affected only one copy of the gene, she didn’t develop the disease.
Her family was offered genetic testing, but refused. They were advised on the importance of sun protection to avoid triggering skin blisters.
At a follow-up visit a year later, the girl’s face lesions worsened, but the blisters on her hands, arms, and feet eased because the recommendations for sun-protective sleeves and clothing, broad-spectrum sunscreen, sun avoidance, and careful wound care were followed.
With signs of cellulitis, a common bacterial skin infection in skin blisters, the girl received a 10-day course of treatment with the antibiotic cephalexin, which led to modest improvements. A multidisciplinary team was set up to conduct a close-follow-up, given her complex clinical scenario.
“A multidisciplinary treatment strategy must be utilized for optimal outcomes that address not only symptom management, but the psychosocial impacts that the condition may place on the patient and their family,” the researchers wrote, nothing the case “underscores the importance of considering porphyria in all blistering [skin conditions] and the importance of [tissue] analysis in diagnosis.”