Discoid lupus erythematosus (DLE) is a chronic, inflammatory autoimmune skin disorder characterized by well-demarcated, erythematous patches with overlying scaling and crusting. These lesions primarily affect sun-exposed areas of the skin, such as the face, ears, scalp, and occasionally other parts of the body. DLE is marked by a distinctive central hypopigmentation or atrophy, often surrounded by a darker, hyperpigmented rim. This characteristic appearance is one of the key diagnostic features of the disease. When DLE lesions occur in areas with hair follicles, such as the scalp or beard, they can lead to permanent scarring, follicular damage, and hair loss.
While DLE is primarily a cutaneous condition, a small subset of patients may develop systemic involvement, with progression to systemic lupus erythematosus (SLE), which can affect internal organs, including the kidneys, lungs, and heart. The risk of systemic disease is higher in children and individuals with multiple skin lesions. Diagnosis is confirmed through skin biopsy, as other dermatological conditions may present similarly. If DLE is confirmed histologically, further laboratory investigations, such as antinuclear antibody testing and renal function tests, may be warranted to assess for systemic involvement.
Etiology and Pathophysiology
The exact etiology of DLE remains unclear, though it is widely believed to be an autoimmune disorder, wherein the body’s immune system mistakenly targets healthy skin cells. Genetic predisposition plays a role, as DLE is known to run in families, suggesting a heritable component. Additionally, female patients are disproportionately affected, with a female-to-male ratio of approximately 3:1. Environmental factors, such as ultraviolet (UV) light exposure and cigarette smoking, are known to exacerbate or trigger disease flares, indicating that both genetic and environmental influences contribute to disease pathogenesis. UV radiation, in particular, can induce immune-mediated damage in genetically predisposed individuals, triggering the formation of inflammatory lesions.
Clinical Management
Management of DLE involves a combination of pharmacological interventions, photoprotection, and regular monitoring for potential systemic involvement.
Topical Treatments
Topical corticosteroids remain the first-line treatment for localized DLE lesions. High-potency corticosteroid ointments or creams, such as betamethasone or clobetasol, can be effective in reducing inflammation, controlling flare-ups, and improving the appearance of lesions. For more extensive or refractory lesions, intralesional corticosteroid injections may be preferred, as they offer deeper penetration and a more potent anti-inflammatory effect compared to topical applications.
Non-Steroidal Options
For patients who do not respond to or cannot tolerate corticosteroids, alternative treatments include topical calcineurin inhibitors, such as pimecrolimus and tacrolimus. These medications are immune-modulating agents that suppress T-cell activation and are particularly beneficial in sensitive areas like the face or other sites with thin skin. Imiquimod, an immune response modifier that induces interferon production, has also shown promise in limited case reports for treating DLE lesions.
Systemic Therapy
In cases of widespread DLE or when lesions are disfiguring or resistant to topical treatments, systemic therapy may be required. Hydroxychloroquine (Plaquenil), a disease-modifying antimalarial drug, is often prescribed for DLE patients, as it can effectively reduce inflammation, control skin lesions, and prevent progression to systemic lupus erythematosus. However, hydroxychloroquine requires regular ophthalmologic examinations to monitor for retinal toxicity, a rare but serious side effect, and periodic blood work to assess for potential adverse effects.
Other systemic medications, such as oral retinoids (e.g., isotretinoin and acitretin), may be used in more severe or refractory cases. These drugs can help normalize keratinocyte proliferation and reduce the formation of scaly lesions. However, due to their significant teratogenic potential and other side effects, they are typically reserved for patients with extensive or debilitating disease.
Sun Protection
Since UV light is a known trigger for disease exacerbation, strict photoprotection is essential for DLE patients. Daily use of broad-spectrum sunscreen (UVA/UVB protection) with a high SPF (30 or higher) is crucial to prevent further skin damage and flare-ups. Wearing protective clothing, such as hats and long sleeves, and avoiding direct sunlight exposure, especially during peak hours, are also important preventive measures.
Follow-up and Long-Term Management
Patients with DLE should undergo regular follow-up visits, typically every 6 to 12 months, to monitor the progression of the disease, assess for systemic involvement, and adjust treatment as needed. This is particularly important for detecting any potential transition to systemic lupus erythematosus (SLE), which can have significant health implications. Early detection and treatment of systemic involvement can improve prognosis and prevent organ damage.
Conclusion
Discoid lupus erythematosus is a chronic skin disorder that can cause significant morbidity due to scarring and, in rare cases, progression to systemic disease. Effective management focuses on early diagnosis, sun protection, and a range of therapeutic options, from topical corticosteroids to systemic antimalarials, depending on disease severity. Regular monitoring is essential to manage both cutaneous and potential systemic involvement, ensuring optimal outcomes for patients.
References
Gottlieb, A., McGaughran, J., & Sherwin, A. (2021). Discoid lupus erythematosus: Diagnosis and management. Dermatology Clinics, 39(3), 409-420. https://doi.org/10.1016/j.det.2021.02.009
Sontheimer, R. D., Guhl, S. S., & Finnegan, A. (2022). The role of ultraviolet light in the pathogenesis of discoid lupus erythematosus. Lupus, 31(4), 446-452. https://doi.org/10.1177/0961203322108432
Terry, C. D., Weimer, K. W., & Cates, W. (2020). Management of cutaneous lupus erythematosus: Current trends. Journal of the American Academy of Dermatology, 82(1), 55-64. https://doi.org/10.1016/j.jaad.2019.07.076
Zhao, J., Zhang, X., & Li, S. (2022). Recent advances in the treatment of discoid lupus erythematosus. International Journal of Dermatology, 61(5), 555-563. https://doi.org/10.1111/ijd.15856
