A few days after a four-year-old Japanese boy got over an ordinary upper respiratory infection, he told his parents that people’s faces looked wrong. They took him to an eye clinic. His eyesight was fine, 1.2 in both eyes, with normal eye movements, normal pressures, normal light reflexes, and no astigmatism.
Then someone looked at his drawings. In the portraits he brought with him, the faces, ears, and hair were stretched, both vertically and horizontally, while the rest of the picture was not.
Those drawings became the diagnostic evidence. Pediatricians and an ophthalmologist at Tokyo Medical University published the case in Cureus. To their knowledge, it is the first reported instance of prosopometamorphopsia beginning in early childhood, and the first in which an infection appears to have triggered it.
The Portraits Were the First Clue Anything Was Wrong
Prosopometamorphopsia, or PMO, is a disorder in which human faces appear distorted while everything else in the visual world looks normal. It picked up the nickname demon face syndrome in popular coverage after researchers visualized one man’s distortions in The Lancet, because in some adult cases the faces look grotesque and frightening.
It is very rare, and in a small child it is close to impossible to describe out loud. A four-year-old does not have the vocabulary to recognize that the proportions of faces are wrong while objects stay fine.
The authors flagged this as one reason pediatric cases likely go unreported. Recognizing subtle perceptual distortion in a young child is difficult, the diagnosis leans heavily on self-reported symptoms, and routine practice rarely includes systematic visual perception testing. Their patient’s drawings solved that problem, giving clinicians something objective to look at. Some were partly assisted by his mother, and one figure in the paper is a portrait of the boy’s brother that she drew from his descriptions.
Every Test Came Back Normal Except One Antibody Titer
After the eye clinic referred him, the workup was thorough. He had no neurological abnormalities on examination. Urinalysis, chest and abdominal radiography, brain MRI, magnetic resonance angiography and an electroencephalogram all came back without obvious abnormalities.
Developmental and psychological testing was also normal. His intelligence quotient measured 123 on the Tanaka-Binet Intelligence Scale, and a parent interview rating scale showed no tendency toward autism spectrum disorder. He was born at full term, had reached his milestones normally, and had no family history of epilepsy, migraine, dementia or psychiatric illness.
The one abnormal result was serologic. His blood showed elevated antibodies to Mycoplasma pneumoniae at a titer of 1:160.
That bacterium is a common cause of respiratory infection, best known in the United States as the usual culprit behind walking pneumonia. The CDC estimates that roughly 2 million M. pneumoniae infections occur in the country each year, most of which are mild. The agency recorded a large increase in 2024, unusual because it reached young children rather than mainly school-age kids and adolescents. Infections have been declining since the start of 2025, though they remain elevated in some regions. Neurological complications are recognized but uncommon, and the mechanisms underlying them remain a subject of active research.
Why Face Perception Can Break While Everything Else Looks Fine
The reason a distortion can be limited to faces is how the brain processes them. Face processing runs through a dedicated network of specialized regions, and one influential model holds that perceptual distortions arise from an imbalance of activity across that face-selective network, which can gradually recalibrate over time.
In adults, PMO is most often linked to posterior cortical lesions, brain infarction, hemorrhagic stroke, migraine, epilepsy, or surgical complications. A century-spanning review of the condition published in Cortex found that bilateral or non-lateralized facial distortion was most often associated with right-hemisphere lesions (61 percent) or bilateral lesions (30 percent). That same review identified the youngest previously reported PMO patient as 19 years old.
None of that fits this boy, whose imaging was clean. The authors propose instead that an autoimmune or inflammatory process following M. pneumoniae exposure disrupted the face-processing network, and they point to a previously reported seven-year-old girl who developed Alice in Wonderland syndrome after mycoplasma infection, seeing her mother’s face and fingers as smaller than before.
They are explicit about the weakness in that reasoning. A mildly elevated antibody titer does not establish that a prior infection caused the condition; no imaging findings support the proposed disruption; and no spinal fluid or PCR testing was performed. It remains a hypothesis built on timing and the absence of alternatives.
A Year Later, Nothing Has Changed
Most people with PMO recover, sometimes in hours and sometimes over years. This boy has not. At the time of writing, he was five, and his distortion persisted unchanged, neither worsening nor resolving. His development and psychological status remain normal, and he continues to be under periodic follow-up.
The authors’ closing point is not really about neurology. It is about how adults respond when a small child says something impossible.
When a child reports that faces look distorted, they write, clinicians should take the complaint seriously rather than dismissing it as imagination or play, and PMO belongs in the differential diagnosis. They note that in a previously reported 12-year-old boy, fear caused by the distortions significantly impaired his social functioning. Explaining the condition to a child and family, they argue, is a meaningful part of care even when no treatment exists.
There is no specific treatment for PMO. Where an underlying cause can be identified and treated, symptoms may improve sooner. Parents whose child describes persistent, unexplained changes in how things look should raise it with a pediatrician rather than waiting for it to pass.
Key Questions Answered
What is prosopometamorphopsia? It is a rare disorder in which human faces appear distorted while other objects look normal. It is considered one of roughly 40 types of perceptual distortion grouped under the umbrella of Alice in Wonderland syndrome.
How did doctors figure out what a four-year-old was seeing? Through his drawings. In portraits he brought to the clinic, faces, ears,, and hair were elongated both vertically and horizontally, providing clinicians with objective evidence that matched his complaint.
What is the suspected cause? The authors hypothesize an autoimmune or inflammatory process following Mycoplasma pneumoniae exposure, based on the timing and an elevated antibody titer. Imaging and EEG found no structural or epileptic cause.
Does a mycoplasma infection put children at risk of this? There is no evidence that it does at any meaningful rate. M. pneumoniae infections are common and usually mild, and this is a single case in which the connection is proposed rather than proven.
Did the boy get better? No. A year on, at age five, his distortion was unchanged. His development and psychological status remain normal, and he continues to be under follow-up.
What should parents do if a child says faces look wrong? Raise it with a pediatrician rather than dismissing it. The authors emphasize that children reporting perceptual distortions may genuinely be experiencing them.
