Acrodynia is a painful, full-body reaction to mercury poisoning that predominantly strikes young children, producing swollen pink hands and feet, severe irritability, and a cascade of nervous system symptoms. Once known as “pink disease,” it puzzled doctors for decades before being traced to mercury in common household products like teething powders. Though the epidemic form of acrodynia has largely vanished from countries that banned mercurial consumer goods, the condition still appears sporadically wherever children encounter mercury in their environment.
How Acrodynia Was Recognized
In January 1920, a Portland physician named Joseph Bilderback presented ten baffling pediatric cases to the North Pacific Pediatric Society in Seattle. He described children with profuse sweating, swollen red hands and feet that were cold and clammy, peeling skin, and extreme pain when touched.1JAMA Network. Acrodynia—Postmortem of a Disease Bilderback could not explain what caused the condition, and for roughly thirty years, neither could anyone else. Cases accumulated across the English-speaking world throughout the early twentieth century, with entire wards of children presenting the same mysterious cluster of symptoms.
The breakthrough came when researchers eventually linked acrodynia to mercury, and in particular to the mercury-containing teething powders that parents routinely rubbed on their infants’ gums. These products were widely available and aggressively marketed.2PubMed. The rise and fall of pink disease Once mercury-laced teething powders and other mercurial products were pulled from shelves, the epidemic essentially ended. The story of acrodynia became one of medicine’s clearest examples of a mass poisoning hiding in plain sight inside a consumer product.
What the Condition Looks and Feels Like
The name “pink disease” comes from the most visible symptom: the hands and feet turn a deep, dusky pink or red, swell up, and begin to peel. A child’s cheeks and the tip of the nose often flush scarlet as well. The full picture, though, goes far beyond skin changes. Detailed clinical descriptions from the mid-twentieth century catalogued an alarming range of problems: alopecia, salivation heavy enough to soak clothing, loss of teeth, occasional loss of fingernails or even fingertip bones, rashes that came and went, severe muscle weakness, itching, burning pain in the extremities, rapid heart rate, high blood pressure, sensitivity to light, insomnia, and a characteristic emotional pattern of apathy broken by episodes of extreme irritability.3JAMA Pediatrics. Adverse Mercurial Reactions in the Form of Acrodynia and Related Conditions
The skin findings alone can be striking. Case reports describe peeling of the palms and soles, inflamed gums, and an unusual rash concentrated on the hands and feet.4JAMA Dermatology. Cutaneous Manifestations of Acrodynia (Pink Disease) Parents often notice that the child refuses to walk or crawl because the soles of the feet are so painful that any contact is unbearable. The combination of misery, sleeplessness, and inconsolable crying in an otherwise previously healthy toddler is what often drives families to seek emergency care.
The Nervous System in Overdrive
Much of acrodynia’s misery traces back to what mercury does to the nervous system. Research from the 1930s and 1940s documented that affected children showed clear signs of a sympathetic nervous system running too hot: rapid heartbeat, profuse sweating, elevated blood pressure, high blood sugar, and emotional instability. At the same time, there was evidence that the parasympathetic branch was also overstimulated, with increased nasal secretion, drooling, and abdominal pain. On top of both of those, more diffuse nerve involvement showed up as muscle weakness and altered sensation in the limbs.5American Journal of Diseases of Children. Tests of Function of Vegetative Nervous System in Acrodynia
The result is a child whose entire autonomic regulation seems haywire. Body temperature fluctuates. Blood pressure can spike to levels alarming enough in a toddler to trigger a workup for serious cardiovascular or endocrine disease. The sweating is so severe that children can become dehydrated. And the irritability is not ordinary fussiness; affected children have been described as inconsolable for hours, alternating with periods of flat, withdrawn apathy. For parents, this behavioral swing is often the most distressing part of the illness, because the child seems to be in constant suffering without any obvious external cause.
Why Mercury Causes These Symptoms
The mechanism behind the autonomic chaos is now well understood. Mercury interferes with an enzyme called COMT, which is responsible for breaking down the body’s stress hormones: norepinephrine, epinephrine, and dopamine. Normally, COMT needs magnesium and a helper molecule to function. Mercury displaces the magnesium, essentially jamming the enzyme and preventing it from doing its job. The result is that stress hormones pile up in the body instead of being cleared away.6PubMed Central. Mercury Toxicity Mimicking Pheochromocytoma
This accumulation of stress hormones explains the rapid heart rate, the high blood pressure, the sweating, and the agitation. It also explains why mercury poisoning can look so much like a catecholamine-secreting tumor: the blood tests come back with the same elevated hormone levels.7PubMed Central. Temporary Thyroid Dysfunction and Catecholamine Excess Due to Mercury Poisoning in 6 Cases The difference is that in acrodynia the source is blocked enzyme activity, not a tumor producing excess hormones. Once mercury is removed from the body and COMT function recovers, the hormone levels normalize and the symptoms resolve.
Why Only Some Children Got Sick
One of the puzzles that hung over the pink disease era was that many children were exposed to mercury-containing teething powders, but only a fraction developed acrodynia. Siblings sharing the same product could have completely different outcomes. This strongly suggested that individual biology played a role, and recent genetic research supports that suspicion.
A study comparing people who had been diagnosed with pink disease as children against age- and gender-matched healthy controls found significant differences in two genes. Variations in the gene for paraoxonase 1 (PON1) and the gene for MTHFR, an enzyme involved in processing folate, were both more common in the pink disease group.8PubMed Central. Genetic variation associated with hypersensitivity to mercury Both of these genes are involved in how the body handles oxidative stress and detoxification. The implication is that certain people are genetically predisposed to react more severely to mercury exposure, developing full-blown acrodynia at doses that would cause no obvious harm in someone with a different genetic makeup.
This finding reframes the old mystery. It was never that teething powders were “safe for most children.” It was that some children’s biochemistry left them especially vulnerable to a toxin that was harming everyone to some degree but causing overt disease only in those with the least capacity to compensate.
Diagnostic Pitfalls and Look-Alikes
Acrodynia is easy to miss when a physician has never seen it. Mercury poisoning is uncommon in developed countries today, and the condition’s wide-ranging symptoms can point in several misleading directions before anyone thinks to test for mercury.
The most dangerous diagnostic confusion is with pheochromocytoma, a rare tumor that churns out excess stress hormones. A child with acrodynia can present with high blood pressure, a rapid pulse, elevated catecholamine levels on lab work, and episodes of sweating and agitation, which is exactly the clinical picture of a catecholamine-secreting tumor. Case reports describe children undergoing extensive and sometimes invasive workups for a tumor before the true cause was discovered.9Pediatric Emergency Care. Elemental Mercury Poisoning Presenting as Hypertension in a Young Child The key differentiator is asking about mercury exposure, which can be easy to overlook when the family does not realize a mercury source is present in the home.
Kawasaki disease is another look-alike, and the overlap is substantial enough to have generated its own body of literature. Both conditions produce red, swollen, peeling hands and feet; fever; rashes; and irritability in young children. Most of the diagnostic criteria used to identify Kawasaki disease overlap with the features of acrodynia.10PubMed. Kawasaki’s disease, acrodynia, and mercury The concern is not just academic: if a child with mercury poisoning is misdiagnosed with Kawasaki disease, they receive immunoglobulin therapy instead of chelation, and the underlying poisoning goes untreated. Clinicians evaluating any child who fits the Kawasaki pattern should consider mercury testing as part of the differential, especially if the clinical picture is not quite textbook or if the child fails to respond to standard treatment.
Where Mercury Exposure Comes From Today
The teething-powder era is long over, but mercury has not disappeared from everyday life. The sources are just less obvious, which is part of what makes modern acrodynia cases so difficult to catch early.
Broken mercury thermometers and barometers remain a classic household source. Elemental mercury in liquid form is fascinating to children: it forms shiny, rolling beads that invite handling and playing. When spilled on carpet or in enclosed spaces, the mercury evaporates slowly, producing chronic low-level vapor exposure that can build up over weeks or months. Case reports continue to document children developing acrodynia after mercury spills in homes, sometimes from thermometers and sometimes from other household items containing elemental mercury.11PubMed Central. Mercury Toxicity Mimicking Pheochromocytoma
Skin-lightening creams are a more recently recognized and growing source. Some products marketed for skin whitening, particularly those sold informally or imported without regulatory oversight, contain mercury as an active ingredient.12Current Medicine Research and Practice. Current status of mercury level in skin whitening creams A parent using such a cream may unknowingly expose a child through skin-to-skin contact, contaminated surfaces, or mercury vapor released from the product. These cases are particularly insidious because the parent has no reason to suspect that a cosmetic product is a poison source.
Other modern exposure routes include certain folk remedies, religious or cultural ritual uses of liquid mercury, old latex paint in homes (some interior paints manufactured before the 1990s contained phenylmercuric compounds as a preservative), and occupational take-home exposure when a parent works in an industry that uses mercury, such as artisanal gold mining or certain types of manufacturing. In each of these scenarios, the child’s exposure is indirect, and the connection to mercury may never be made unless someone thinks to ask.
How Acrodynia Is Treated
Once mercury poisoning is identified, the first step is straightforward: remove the source of exposure. If mercury vapor in the home is the problem, the family needs professional hazardous-materials cleanup, not just airing out a room. If a product is the source, it needs to be discarded safely.
The medical treatment is chelation therapy, which uses a drug that binds to mercury in the body and allows it to be excreted in the urine. One commonly used chelation agent is succimer (also known by its chemical name DMSA), given by mouth. In a recent case, a child with acrodynia received succimer at a standard dosing protocol: three times a day for the first five days, then twice a day for another ten days. Within a week of starting treatment, her symptoms began improving. The painful extremities, rash, irritability, and insomnia all gradually resolved, and her blood pressure returned to normal.13JCEM Case Reports. Mercury Toxicity Mimicking Pheochromocytoma
Recovery can take weeks to months, depending on the severity and duration of exposure. Blood and urine mercury levels are tracked over time to confirm that the body’s burden is declining. Some children need more than one round of chelation. Supportive care during recovery can include pain management for the extremity pain, treatment for high blood pressure if it persists, and attention to nutrition and hydration, since many affected children have been eating and drinking poorly for weeks by the time they are diagnosed.
Recognizing the Pattern Early
The biggest barrier to treating acrodynia is recognizing it in the first place. The condition is rare enough today that most pediatricians will never see a case, yet common enough that cases continue to be published in the medical literature every few years. The children who fare best are those whose clinicians or parents connect the dots early, often because someone asks the right environmental question.
A practical rule of thumb: any previously healthy young child who develops painful pink or red hands and feet, unexplained high blood pressure, excessive sweating, behavioral changes (especially the characteristic pattern of inconsolable irritability alternating with listless withdrawal), and peeling skin of the palms or soles should have a urine mercury level checked. The test is inexpensive and widely available. The alternative, pursuing lengthy and sometimes invasive workups for tumors or autoimmune disease, is costlier, more stressful, and delays the treatment that actually works.
Families can reduce risk by removing mercury-containing items from the home. Digital thermometers have made mercury thermometers unnecessary. Old barometers, manometers, and mercury switches in antique appliances should be disposed of through a household hazardous-waste program rather than thrown in the trash. And any cosmetic product that does not clearly list its ingredients, particularly imported skin-lightening creams, should be treated with suspicion.
The Genetic Angle and Broader Implications
The discovery that genetic variants in PON1 and MTHFR predispose some people to mercury hypersensitivity raises questions that extend well beyond acrodynia itself.14PubMed Central. Genetic variation associated with hypersensitivity to mercury These same genetic pathways are involved in handling other environmental toxins, and the MTHFR variants in particular are common in the general population. This means a substantial fraction of people may be more vulnerable to mercury than average, without knowing it.
For now, there is no practical screening test that families can use to determine whether a child is genetically susceptible. The genetic findings are research-grade, not something a pediatrician would routinely order. But the concept matters: it underscores that “safe” levels of mercury exposure are population averages that do not account for individual variation. A mercury level that produces no symptoms in one child can produce full-blown acrodynia in another. This is one reason public health authorities tend to err on the side of minimizing mercury exposure for everyone, rather than setting a threshold and declaring anything below it safe. The old teething-powder story demonstrated, at enormous cost, that assuming a toxin is harmless until proven otherwise is the wrong default.