Background: Red lunulae have only rarely been described in patients with lupus erythematosus.
Objective: We assessed the frequency and classified the type of red lunulae in patients with definite lupus erythematosus seen in an interdisciplinary dermatorheumatologic outpatient clinic.
Methods: We studied 56 patients with either systemic or cutaneous lupus erythematosus for the presence of red lunulae.
Results: Eleven of 56 patients (19.6%) with lupus erythematosus had red lunulae. All of them showed a complete type of red lunulae, which was seen on all finger nails in 10 patients and on a single finger nail in 1 patient. Seven patients suffered from systemic lupus, the other from subacute cutaneous (n = 2) or chronic discoid cutaneous lupus (n = 2). There was no statistically significant difference in autoantibody expression or treatment regimen between patients with or without red lunulae. However, symptomatic patients had a shorter disease interval, and all but 1 showed either periungual erythema or chilblain lupus. Periungual erythema was not observed in any patient without red lunulae.
Conclusion: Red lunulae, although rarely described in the literature, are not an uncommon symptom of patients with lupus erythematosus. They seem to be associated with periungual erythema or chilblain lupus. Red lunulae should be considered in the clinical spectrum of lupus disease.