Subacute cutaneous lupus erythematosus (SCLE), discoid lupus erythematosus (DLE), and systemic lupus erythematosus (SLE) are three of the distinctive subsets of lupus erythematosus (LE). Peter Schur, in 1971, coined the term “rhupus” to describe the patients satisfying the criteria of both SLE and rheumatoid arthritis (RA)1. In 2013, the globally cumulative number of rhupus cases reported was about 1402. RA combined with SCLE has also been reported, while the RA with DLE has never been described. Herein, we report a case of RA, who developed DLE after 10 years of RA.
In June 2017, a 55-year-old man developed a pink patch on the scalp. A few weeks later, similar lesions appeared on his forehead, nose, temporal region, and forearms (Fig. 1A). The patient had a 25-year history of RA that had resulted in severe joint damage of the hands and knees. At the time of presentation, the patient was taking 50 mg of diclofenac sodium twice daily and 4 mg of methylprednisolone once daily for his RA. He had been taking the diclofenac sodium for approximately 10 years. He denied a history of oral ulcers, alopecia, chest pain, pleurisy, or sicca complex. The patient did not seek medical attention at the time due to his poor social economic status. In early December 2017, the patient visited a rheumatologist for knee joint pain. The doctor prescribed weekly treatment with 10 mg of methotrexate and advised him to consult a dermatologist for the skin lesion.
Due to a lack of DLE lesion improvement, the patient visited a dermatology clinic two weeks later. Upon examination, the patient showed severe RA with bilateral ulnar deviation and destructive changes in all fingers along with swelling in both wrists and in the left knee (Fig. 1B). Radiographic examination revealed significant destruction of joints, including carpus, metacarpophalangeal joints, and interphalangeal joints.
Examination of the skin revealed pink patches on the head, nose, temporal region, and extensor surface of the forearms. Skin biopsy followed by a histological examination of the lesion revealed a marked atrophy of the epidermis and liquefaction degeneration of the basal cell layer. Capillary proliferation along with lymphocyte and histiocyte infiltration in the superficial dermis and around the blood vessels of appendages were also observed (Fig. 2A and 2B). Results of serological examination were as follows: antinuclear antibody (ANA): positive (homogeneous); immunoglobulin (Ig)G: 19.30 g/L (normal range: 7.51–15.6 g/L); positive rheumatoid factor: titer of 1:2,410 IU/ml (normal level: <20 IU/ml); anti-streptolysin (ASO) antibody: 143 IU/ml (normal level: < 116 IU/ml); anti-cyclic citrullinated peptide antibody: 47.40 RU/ml (normal level: <25 Ru/ml); and erythrocyte sedimentation rate (ESR): 66 mm/h (normal level: < 15 mm/h). The results of anti-native DNA assays were negative or normal. Tests for antibodies against Ro (SS - A) or La (SS - B) also produced negative results.
The patient was subsequently treated with 100 mg of hydroxychloroquine sulfate twice daily along with topical clobetasol propionate. He gradually got better within one month. As of the time of writing, the patient is still being followed up.
Hereditary predisposition, viral infection, drugs, ultraviolet radiation, and gonadal hormones are all thought to be related to LE. Single or multiple, round or oval, sharply demarcated, rose-pink lesions accompanied by adherent scaling and follicular dilation typically appear on sun-exposed sites. These lesions tend to appear most often on the face, scalp, and auricular regions, and the eruptions are often aggravated by sun exposure. DLE in particular is closely related to sun exposure. One report indicates that 1.3% -5.0% of DLE may develop into SLE3, whereas another suggests that up to 17% of DLE may develop into SLE4. Furthermore, 15% of SLE patients have DLE skin lesions.
There are many reports about RA combined with LE. The coexistence of RA with SLE is known as rhupus syndrome, the prevalence of which is 0.09%5. Previous work showed that rhupus patients have milder SLE activity and a lower incidence of visceral organ involvement compared with SLE patients without RA6-7. The exact etiology and triggers of rhupus remains unknown till date. There are also several reports of RA combined with SCLE8-9. Migita et al.6 reported a case of RA with Sjögren's syndrome (SS) in which the patient developed SCLE; serological tests showed that the patient's anti-SS-A/Ro antibody and anti-DNA antibody levels were elevated. Additionally, Pantoja et al.9 reported the case of a 51-year-old woman with RA who developed anti-La/SSB antibodies and erythematosquamous lesions on her upper back; the histological diagnosis was SCLE.
Our patient presented multiple unusual clinical features. First, his DLE occurred after a 25-year history of RA. The patient had no history of extensive sun exposure prior to the appearance of the eruption, and his laboratory evaluation results were unremarkable, except for a positive ANA (homogeneous) finding. Based on these initial findings, a diagnosis of DLE without associated systemic disease was made. Two weeks later, a rheumatologist prescribed methotrexate to the patient, but this treatment failed to improve his DLE lesions. However, the patient improved after he was treated with hydroxychloroquine sulfate and topical clobetasol propionate. Notably, the patient's lesions were disseminated, so he has an increased risk of his condition developing into SLE; thus, further follow-up of this patient is necessary.
This work was supported by Chinese Society Dermatology Bright Future foundation.
. Schur PH. Systemic lupus erythematosus. In: Beeson PB, McDermott W, eds. Cecilloeb Textbook of Medicine. 13th ed. Philadelphia, PA: WB Saunders; 1971:821.
. Iaccarino L, Gatto M, Bettio S, et al Overlap connective tissue disease syndromes. Autoimmun Rev 2013;12(3):363–373. doi: 10.1016/j.autrev.2012.06.004.
. Chong BF, Song J, Olsen NJ. Determining risk factors for developing systemic lupus erythematosus in patients with discoid lupus erythematosus. Br J Dermatol 2012;166(1):29–35. doi: 10.1111/j. 1365-2133.2011.10610.x.
. Gronhagen CM, Fored CM, Granath F, et al Cutaneous lupus erythematosus and the association with systemic lupus erythematosus: a population-based cohort of 1088 patients in Sweden. Br J Dermatol 2011;164(6):1335–1341. doi: 10.1111/j.1365-2133.2011.10272.x.
. Sarkar S, Saha K. Bilateral acute lupus pneumonitis in a case of rhupus syndrome. Lung India 2012;29(3):280–282. doi: 10.4103/0970-2113.99119.
. Li J, Wu H, Huang X, et al Clinical analysis of 56 patients with rhupus syndrome: manifestations and comparisons with systemic lupus erythematosus: a retrospective case-control study. Medicine 2014;93(10):e49. doi: 10.1097/MD.0000000000000049.
. Simon JA, Granados J, Cabiedes J, et al Clinical and immunogenetic characterization of Mexican patients with ‘rhupus’. Lupus 2002;11(5):287–292. doi: 10.1191/0961203302lu189oa.
. Migita K, Udono M, Kimura H, et al Association of subacute cutaneous lupus erythematosus in rheumatoid arthritis patient with Sjögren's syndrome. Mod Rheumatol 2002;12(4):354–356. doi: 10.3109/s101650200064.
. Pantoja L, González-López MA, Bouso M, et al Subacute cutaneous lupus erythematosus in a patient with rheumatoid arthritis. Acta Rheumatologica Scandinavica 2002;31(6):377–379. doi: 10.1080/030097402320817130.