(CNN)Eczema is a common skin condition that can pack a profound psychological punch: People with eczema are more likely to have suicidal thoughts and suicide attempts than others without the condition, according to new research published Wednesday in the journal JAMA Dermatology.
Eczema patients at 36% higher risk of suicide attempts, study says
Eczema, also known as atopic dermatitis, is a skin disease that's chronic and inflammatory -- meaning it involves an immune system reaction. It affects 18 million adults (more than 7%) and 9.6 million children (13%) in the United States, according to the researchers from University of Southern California Keck School of Medicine.
They analyzed 15 previous studies that included 310,681 eczema patients and about 4.4 million patients without eczema. Study locations were in North America, Asia, Europe and Africa.
The researchers found that patients with eczema were 44% more likely to have suicidal thoughts and 36% more likely to attempt suicide compared to people without the skin condition. However, due to incomplete data or inconsistent results, the researchers did not find a difference in the risk of completed suicide between eczema patients and others.
So what explains the higher rate of self-destructive thoughts and actions?
The study authors explain that eczema is associated with an increase in proinflammatory cytokines, a type of immune system molecule found at high levels wherever there is an infection. Higher levels of proinflammatory cytokines in the central nervous system may disrupt the balance of neurotransmitters in the brain and lead to negative thoughts, they theorized.
Dr. Joel M. Gelfand, a professor of dermatology and of epidemiology and medical director of the Dermatology Clinical Studies Unit at the University of Pennsylvania Perelman School of Medicine, told CNN the possibility of cytokines disrupting brain chemistry is only "a theory."
"The causal role of inflammation and suicidal activity and outcomes is not established yet," said Gelfand who was not involved in the analysis. Still, he believes the new research is "important."
"The country is facing an epidemic in suicide, it's really a public health crisis, and the more we can understand what conditions and behaviors lead to suicidal thinking, behavior and actions, the more we can figure out ways to identify people at risk and hopefully prevent these really terrible outcomes for people," Gelfand said.