Addressing Skin Pain in Atopic Dermatitis

For the estimated 7% of adults in the United States who suffer from atopic dermatitis, their burden often extends beyond the immediate dermatologic effects of the disease.¹ A wide range of comorbid conditions has been observed in this patient population, including asthma, cardiovascular disease, diabetes, and autoimmune disease, as well as psychological disorders such as depression and anxiety.¹ In addition, results of emerging research highlight the association of skin pain with atopic dermatitis, including recent studies reporting skin pain in 43% to 78% of patients with eczema.^2,3

“Several explanations for the associated skin pain may be put forward, including a burning skin sensation from [atopic dermatitis] and topical medication, as well as painful fissured skin,” wrote Jacob P. Thyssen, MD, PhD, and colleagues at the University of Copenhagen in Hellerup, Denmark, in a cross-sectional study published online in September 2019 in the British Journal of Dermatology.⁴ However, there are no widely accepted consensus recommendations regarding assessment or treatment of pain in atopic dermatitis and there are scant data pertaining to its characteristics and etiologic mechanisms.

Although “research shows that, for the most part, pain in atopic dermatitis is attributable to scratching and underlying itch, a subset of patients have reported that their skin pain was either unrelated or partially related to scratching,” said Saakshi Khattri, MD, assistant professor of dermatology, rheumatology, and internal medicine at the Icahn School of Medicine at Mount Sinai in New York, New York, in an interview. “It is likely that some patients experience the sensation of pain secondary to underlying inflammation in the skin and/or neurosensory dysfunction.”  

Latest Findings

To further explore the relationship between eczema and skin pain, Thyssen et al investigated the characteristics of skin pain in patients with atopic dermatitis and examined the association between this symptom and the number of filled prescriptions for analgesic medications.⁴ The sample included 3834 adults with diagnosed atopic dermatitis (69% women) and 3208 adults from the Danish general population (54% women).

Disease severity was assessed with the Patient-Oriented Scoring of Atopic Dermatitis (PO-SCORAD) tool and the severity of itch and both joint and skin pain were assessed using numerical rating scales of 0 to 10 (indicating a range from no symptoms to very strong symptoms). Data regarding the use of analgesic medication were obtained from the nationwide prescription registry in Denmark.

The results demonstrated asymptomatic (score of 0), mild (score of 1-24), moderate (score of 25-50), and severe disease (score >50), respectively, in 6.8%, 55.5%, 34.0%, and 3.7% of the atopic dermatitis cohort. Compared with a median skin pain score of 0 in the general population and in patients with asymptomatic atopic dermatitis, median skin pain scores in the remaining patient groups were 0 (interquartile range [IQR], 0-2) in those with mild disease, 4 (IQR, 2-6) in those with moderate disease, and 7 (IQR, 6-8) in those with severe disease. Higher joint pain scores were observed only in patients with severe eczema (median score, 4; IQR, 1-7] compared with the general population (median score, 2; IQR, 0-5]).

Skin pain was found to be positively associated with disease severity and itch. In the atopic dermatitis group, higher skin pain scores were noted in the plantar, chest, and palmar areas. There was no significant difference in the use of pain medication among patients with atopic dermatitis compared with the general population.

In another cross-sectional study of 602 adults with atopic dermatitis, researchers from multiple US universities found that 61% of patients reported skin pain, the frequency and intensity of which were associated with PO-SCORAD, PO-SCORAD for itch and sleep, and the Patient-Oriented Eczema Measure (P ≤.004 for all). These results were described in the November/December 2019 issue of the Journal of Allergy and Clinical Immunology: In Practice.⁵

Within the group reporting pain, 48% of patients indicated that it occurred only after scratching, whereas 42% reported intermittent pain and 11% experienced constant pain throughout the day. Pain was linked to open areas due to scratching (27%), fissures in the skin (27%), inflamed red skin (25%), and burning from creams or ointments (10%). “Mild AD was associated with more pain from scratching, whereas severe AD was associated with more constant pain and pain from inflamed skin,” the study authors wrote.⁵

Potential Mechanisms and Remaining Needs

Among the many possible causes of increased pain in atopic dermatitis, research suggests that it “might be related to increased density of dermal nerves in eczema patients compared to controls,” explained Dr Khattri. However, other research “showed lower nerve density in patients vs controls, but individual nerve fibers were longer in lichenified and unlichenified lesions, so it is still unclear whether nerve density plays a role,” she added.²

“That said, these nerve endings appear to be more hyperresponsive to exogenous stimuli secondary to impaired barrier function, so there may also be an increased activation of cutaneous nerves to mechanical and other exogenous stimuli” in atopic dermatitis. There is a need for larger-scale multicenter studies to further investigate these and other potential mechanisms involved in skin pain in this population.

Researchers have also demonstrated that skin pain in eczema is associated with increased self-consciousness and worse mental health and quality of life, underscoring the need for adequate assessment and treatment.²

“In practice, clinicians should ask about pain and assess skin pain severity routinely along with itch severity in all eczema patients, and monitor changes in pain and how they relate to disease activity,” Dr Khattri advised.

References

1. Silverberg JI, Gelfand JM, Margolis DJ, et al. Association of atopic dermatitis with allergic, autoimmune, and cardiovascular comorbidities in US adults. Ann Allergy Asthma Immunol. 2018;121(5):604-612.e3.

2. Vakharia PP, Chopra R, Sacotte R, et al. Burden of skin pain in atopic dermatitis. Ann Allergy Asthma Immunol. 2017;119(6):548-552.e3.

3. Maarouf M, Kromenacker B, Capozza KL et al. Pain and itch are dual burdens in atopic dermatitis. Dermatitis. 2018;29(5):278-281.

4. Thyssen JP, Halling-Sønderby A-S, Wu JJ, Egeberg A. Pain severity and use of analgesic medication in adults with atopic dermatitis: a cross-sectional study [published online September 25, 2019]. Br J Dermatol. doi:10.1111/bjd.18557

5. Silverberg JI, Gelfand JM, Margolis DJ, et al. Pain is a common and burdensome symptom of atopic dermatitis in United States adults. J Allergy Clin Immunol Pract. 2019;7(8):2699-2706.e7.