Low rates of scalp biopsy in patients with systemic lupus erythematosus (SLE) may lead to an overestimation of the prevalence of concomitant alopecia areata (AA), study data published in Dermatologic Therapy suggests. In a cohort of patients with both SLE and non-scarring alopecia, just under a quarter were diagnosed using scalp biopsy. Per these results, investigators advocated for the routine use of scalp biopsy in the examination of patients with SLE and hair loss.
Nonscarring alopecia was added as a diagnostic criterion for SLE in 2012 by the Systemic Lupus International Collaborating Clinics (SLICC). Nonscarring lupus-associated alopecia can closely resemble other forms of nonscarring alopecia, including AA. This resemblance may lead to an overestimation of the relationship between AA and SLE and an underdiagnosis of SLE in patients presenting with hair loss. To better characterize the relationship between SLE and alopecia, investigators conducted a retrospective chart review of patients with SLE and alopecia who received treatment at the Partners Healthcare network in Boston, Massachusetts from 1989 to 2019. Using chart data, investigators computed the rate of biopsy-proven AA in patients with SLE; and the rate of scalp biopsy in patients with SLE who received a diagnosed of nonscarring alopecia.
The study cohort comprised 70 patients, of whom 61% were classified as having nonscarring alopecia. Of the patients with a diagnosis of nonscarring alopecia, only 23.3% had received a scalp biopsy during the diagnostic process. It was found that 29% had scarring of alopecia, among whom 60% were biopsied. An additional 7 patients had both scarring and nonscarring alopecia, among whom 5 57.1% were biopsied. In patients with nonscarring alopecia, the rates of biopsy by diagnosis were 25% for AA, 14.3% for pattern hair loss, 14.3% for nonscarring alopecia, and 100% for telogen effluvium. Of the 10 total biopsies collected from the nonscarring alopecia patient group, 10% yielded histopathological data consistent with a diagnosis of lupus-specific nonscarring alopecia in a patient initially thought to have AA.
Results from this study indicated to the researchers that the majority of patients with SLE and nonscarring alopecia were not diagnosed by scalp biopsy. “[L]ow biopsy rates raise concerns thatclinicians are misclassifying hair loss and overestimating the prevalence of AA in these patients,” investigators wrote. “[T]he findings herein suggest when considering AA in patients who have not met the SLICC criteria, biopsy is warranted…Without biopsy, or trichoscopy, an important SLICC criterion for lupus may be missed due to misclassification of patchy lupus-specific alopecia as alopecia area.”
Sharifzadeh A, Smith GP. Low rate of scalp biopsy in systemic lupus erythematosus patients and the potential for misdiagnosis. Dermatol Ther. Published online May 18, 2021. doi: 10.1111/dth.14991