Discoid Lupus Erythematosus: Causes, Symptoms, and Treatment

What Is Discoid Lupus Erythematosus?

Lupus refers to a group of autoimmune diseases in which the immune system mistakenly attacks the body’s own tissues, most commonly the skin and, in some forms, internal organs. Several variants exist, differing in severity and clinical involvement:

• Systemic Lupus Erythematosus (SLE), the most severe form, affects multiple organ systems
• Cutaneous Lupus Erythematosus: primarily limited to the skin
• Drug-induced Lupus Erythematosus triggered by certain medications
• Neonatal Lupus: occurring in newborns exposed to specific maternal autoantibodies

Focusing on cutaneous forms, clinicians further classify the disease based on its duration and behavior:

• Acute Cutaneous Lupus Erythematosus: sudden onset, almost always associated with systemic disease
• Subacute Cutaneous Lupus Erythematosus: an intermediate form with variable systemic involvement
• Chronic Cutaneous Lupus Erythematosus, also known as Discoid Lupus Erythematosus (DLE), is the focus of this article

This classification is clinically important: while acute cutaneous lupus is strongly associated with systemic involvement, subacute and discoid forms are more often confined to the skin, with a more limited impact on overall health.

DLE is more common in women than men, with a male-to-female ratio ranging from 1:2 to 1:4. It typically begins in young adulthood, most often between 20 and 40 years of age. Individuals with darker skin phototypes may experience more severe disease manifestations.

The characteristic lesions of DLE typically appear on the face, scalp, and sometimes the trunk, presenting as persistent red (erythematous), firm plaques that may be covered by adherent scale. Over time, lesions often evolve toward central pallor and skin thinning (atrophy), eventually leading to permanent scars.

The prognosis is variable. Importantly, in a small proportion of cases (around 5%), DLE may represent an early manifestation of evolving Systemic Lupus Erythematosus, making long-term follow-up essential for all affected patients.

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Causes

The primary cause of DLE is not fully understood. It is an autoimmune disease in which symptoms develop in genetically predisposed individuals (for example, those with a family history of DLE or other autoimmune conditions) following exposure to specific environmental triggering factors, including:

• Ultraviolet (UV) radiation, principally sunlight (both UVA and UVB), which is the most important and well-established trigger
• Infections: certain viral or bacterial infections may precipitate flares
• Psychological stress can trigger or worsen skin manifestations
• Abrupt changes in environmental temperature

The most widely accepted pathophysiological hypothesis is that these triggering factors cause apoptosis (programmed death) of epidermal cells, the outermost cells of the skin. As these cells die, they release proteins (antigens) that are normally sequestered inside the cell. The unexpected presentation of these intracellular proteins to the immune system appears to trigger an inappropriate immune response.

This response is termed autoimmune because it is mounted by the individual’s own immune system against their own cells, rather than against foreign agents such as bacteria or viruses. In DLE specifically, this autoimmune attack is restricted to the skin, without the multi-organ involvement seen in systemic lupus.

Important: Lupus, in all its forms, is NOT contagious. It cannot be transmitted from person to person through any route of contact.

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Symptoms

DLE lesions typically affect the face, particularly the:

• Forehead
• Nose
• Cheeks

When both cheeks are simultaneously involved, the lesions form the characteristic “butterfly rash” (also called malar rash), an erythematous eruption spanning the nose and both cheeks in a wing-like distribution.

Other commonly affected sites include:

• Eyelids
• Ears and the external auditory canal
• Neck
• Scalp

Less frequently, lesions may also develop on the:

• Trunk
• Limbs
• Hands

Evolution of lesions:

• DLE begins as papules, which are small, raised, firm skin lesions. These tend to coalesce into erythematous (red), indurated, persistent plaques, often appearing symmetrically on both sides of the face.

• The plaques are:

  • Round or oval in shape
  • Progressive: they enlarge and merge over time
  • Characterized by hyperesthesia, extreme sensitivity to touch and temperature
  • Often covered centrally by a whitish, adherent scale that is painful when lifted or removed

• The characteristic temporal evolution of DLE lesions follows a predictable pattern:

  1. Active expansion at the periphery of the lesion
  2. Central resolution: the center of older lesions becomes pale, depressed, and atrophic (thinned)
  3. Permanent scarring occurs when the central atrophy is replaced by permanent scars. These may appear as:
     • Pink/white or brown/dark hyperpigmented macules
     • Depressed, smooth, avascular scar tissue

Scalp involvement:

• On the scalp, DLE can cause cicatricial (scarring) alopecia. This condition leads to irreversible loss of hair follicles due to scarring, resulting in permanent bald patches with whitish scar tissue. This is one of the most psychologically distressing complications of DLE.

Mucosal involvement:

• The mucous membranes (lips, oral cavity, tongue, and palate) are affected in fewer than 5% of patients, where manifestations may include:
  • Erythema (redness)
  • Hyperkeratosis (thickening)
  • Dark scarring
  • Ulcerations

Nail involvement:

• Rarely, when nails are affected, they may display abnormal morphology; this condition is known as onchodystrophy.

Key principle: As with all forms of lupus, DLE symptoms can be triggered and significantly worsened by sun exposure. Sun protection is therefore not merely a preventive measure but a fundamental therapeutic one.

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Diagnosis

The diagnosis of DLE is established through an integrated assessment combining:

Clinical examination and medical history:

• The dermatologist evaluates the characteristic morphology, distribution, and evolution of the skin lesions, alongside the patient’s personal and family history of autoimmune disease and history of sun exposure or other triggering factors.

Laboratory investigations:

• Patients with suspected DLE should have antinuclear antibodies (ANA) measured using indirect immunofluorescence techniques. ANA are positive in approximately 25 to 50% of DLE patients, which is a lower rate than in systemic lupus. In systemic lupus, ANA positivity exceeds 95%. Additional autoantibody panels (anti-dsDNA, anti-Sm, anti-Ro/SSA, anti-La/SSB) help assess the risk of systemic disease.

Skin biopsy and histological examination:

• A skin biopsy, which involves removing a small tissue sample from an active lesion, provides definitive histological confirmation of the diagnosis. Characteristic microscopic findings in DLE include:

  • Thinned epidermis with vacuolar degeneration of basal layer keratinocytes (the hallmark of interface dermatitis)
  • Dense lymphocytic infiltrate in the dermis, concentrated around blood vessels and hair follicles (perivascular and perifollicular distribution)
  • Damage to elastic and collagen fibers of the dermis
  • In some cases, lymphocytic infiltration extending into the subcutaneous fat (hypodermis)

• Direct immunofluorescence of a biopsy sample from a lesional area typically shows a positive “lupus band”. This refers to a granular deposition of immunoglobulins (IgG, IgM) and complement (C3) at the dermoepidermal junction.

Differential diagnosis:

DLE must be carefully distinguished from other inflammatory, infectious, or neoplastic conditions with clinically similar presentations:

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Pregnancy and DLE

Women with DLE who wish to become pregnant should ideally plan their pregnancy during a period of sustained disease remission. Experts recommend this remission last at least 6 months before conception. This is because many of the first-choice medications used in DLE management, particularly some immunosuppressants, are teratogenic. These drugs can cause fetal malformations and must be discontinued before and during pregnancy.

Hydroxychloroquine is generally considered the safest antimalarial for use during pregnancy and is often continued throughout gestation when the benefit-to-risk ratio is favorable. However, this must always be an individualized decision made with the treating dermatologist and obstetrician.

Even when disease is well-controlled at the time of conception, flares may occur during the 9 months of pregnancy. This is likely due to the significant hormonal and immunological changes that happen during gestation.

Pre-conception screening is strongly recommended and includes:

• Assessment of antiphospholipid antibodies (anticardiolipin and anti-β2-glycoprotein I antibodies). If positive, these antibodies significantly increase the risk of thrombosis, recurrent miscarriage, and other pregnancy complications, known as antiphospholipid syndrome
• Complete autoantibody panel, including anti-Ro/SSA and anti-La/SSB antibodies. These can cross the placenta; if present in the mother, they carry a small risk of causing neonatal lupus in the newborn, which may include congenital heart block
• Assessment of renal and hepatic function

Close collaboration between the dermatologist, rheumatologist, and obstetrician throughout pregnancy is essential.

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Prognosis and Complications

The long-term course of DLE is unpredictable and varies significantly between patients. Some patients experience a relatively stable, limited disease course, while others show progressive worsening or episodic flares.

Risk of evolution to Systemic Lupus Erythematosus: All DLE patients should undergo periodic clinical and laboratory evaluation for signs of systemic involvement, both at the time of diagnosis and at regular intervals afterward. Approximately 5% of DLE patients will develop overt SLE over the years. Risk factors associated with a higher likelihood of systemic spread include:

• Widespread skin lesions (disseminated DLE)
• High ANA titers
• Presence of anti-dsDNA or anti-Sm antibodies
• Leukopenia or other hematological abnormalities
• Arthritis or other systemic symptoms

Cutaneous complications:

• Permanent scarring alopecia: Perhaps the most psychologically distressing complication. The destruction of hair follicles by the scarring inflammatory process leads to irreversible, permanent bald patches on the scalp, leaving behind whitish scar tissue. Unlike non-scarring forms of hair loss, this cannot be reversed.
• Disfiguring facial scarring: Atrophic scars on the face, especially on the cheeks, nose, and ears, can be severely disfiguring. They often have a major negative impact on quality of life, self-esteem, and social functioning.

Malignant transformation:

• An important but sometimes overlooked complication is the potential for malignant transformation within chronic DLE lesions. Long-standing, particularly atrophic or ulcerated DLE lesions may develop into squamous cell carcinoma (SCC), which is a type of skin cancer. This risk, while relatively low, underscores the importance of regular dermatological surveillance and prompt biopsy of any lesion with atypical features (rapid growth, ulceration, bleeding).

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Treatment

Treatment of DLE is tailored to the extent of skin involvement (localized vs. widespread disease) and the stage of the lesions (early active vs. established scarring).

General principles:

• Treatment is most effective when initiated early, ideally before irreversible atrophy and scarring develop
• Sun protection is an absolutely essential component of treatment, not merely a preventive measure (see Prevention below)
• Regular monitoring for signs of systemic disease is integral to the management plan

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Topical treatments (for early, small, localized lesions):

• Topical corticosteroids: High-potency corticosteroid creams are the first-line treatment for early, limited DLE lesions. Application under occlusion (covering the cream with a dressing or plastic wrap) can significantly enhance penetration and efficacy. Long-term use must be monitored to prevent skin atrophy.
• Topical calcineurin inhibitors (tacrolimus, pimecrolimus): Steroid-sparing alternatives particularly suitable for facial lesions and areas where prolonged corticosteroid use poses risks (eyelids, thin skin).
• Intralesional corticosteroid injections: These are particularly effective for thick, resistant, or hypertrophic plaques. A concentrated corticosteroid solution is injected directly into the lesion.

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Systemic treatments (for widespread, recalcitrant, or severe disease):

• Antimalarial drugs, the cornerstone of systemic therapy for DLE, play a crucial role in treatment

  • Hydroxychloroquine: 200 mg per day (first choice, best safety profile)
  • Chloroquine: 250 mg per day (alternative if hydroxychloroquine is unavailable or not tolerated)

  Antimalarials act as anti-inflammatory agents by interfering with immune activation pathways. They are effective in controlling DLE, but require weeks to months before full therapeutic benefit is seen.

  Important safety monitoring: Both hydroxychloroquine and chloroquine carry a risk of retinal toxicity (maculopathy) with long-term use. Therefore:

  • A complete ophthalmological examination (including fundoscopy and visual field testing) must be performed before starting antimalarial therapy and repeated annually (or more frequently at higher doses or after 5 years of use)
  • G6PD (Glucose-6-phosphate dehydrogenase) enzyme deficiency must be assessed before treatment, as both drugs can precipitate hemolytic anemia in G6PD-deficient individuals
  • Hepatic function should be evaluated before and during treatment

• Systemic corticosteroids: Oral corticosteroids may be used for short courses at the beginning of treatment alongside antimalarials (to achieve rapid initial control) or during severe acute flares. Long-term systemic corticosteroid use is avoided due to significant side effects.

• Immunosuppressive agents: For refractory cases that do not respond to antimalarials, the following second-line immunosuppressants may be employed:

  • Methotrexate: A folate antagonist with anti-inflammatory and immunomodulatory effects; requires regular monitoring of blood counts and liver function
  • Azathioprine: A purine analog immunosuppressant
  • Cyclophosphamide: Reserved for severe or rapidly progressing disease; significant toxicity profile

• Other emerging therapies: Case reports and small series have reported benefit with:

  • Dapsone: Particularly useful for bullous or neutrophil-rich variants
  • Retinoids (acitretin): For hyperkeratotic, treatment-resistant lesions
  • Biological agents (e.g., belimumab, anifrolumab): Currently studied primarily in SLE but showing promise in severe cutaneous lupus

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Prevention

Rigorous sun protection is the single most important preventive strategy for all lupus patients, including those with DLE. Ultraviolet radiation serves as the primary environmental trigger for disease flares and the development of new lesions.

Comprehensive sun protection measures include:

• Broad-spectrum sunscreen (protecting against both UVA and UVB radiation) with SPF ≥ 50 should be applied every day, regardless of the season. This includes both summer and winter, since UVA rays penetrate cloud cover and glass. Additionally, it must be reapplied every 2 hours during prolonged outdoor exposure. Tinted or physical (mineral) sunscreens containing zinc oxide or titanium dioxide are particularly recommended.
• Avoid sun exposure during peak hours: Stay indoors or in the shade between 10 AM and 4 PM, especially during summer months.
• Protective clothing: Wide-brimmed hats, UV-protective long sleeves, and sunglasses with UV protection should be worn routinely outdoors.
• Avoid artificial UV sources: Tanning beds and sunlamps must be completely avoided.
• Avoid other known triggers: Managing stress, avoiding sudden temperature changes, and promptly treating any infections can help reduce flare frequency.

Long-term monitoring:

• All patients with DLE should undergo periodic dermatological follow-up with clinical examination and laboratory tests (ANA panel, complete blood count, urinalysis, renal and hepatic function) to monitor for signs of evolving systemic disease. The frequency of monitoring should be individualized based on disease activity, antibody profile, and presence of risk factors for systemic spread.

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Sources and Bibliography

• Braun-Falco O., Plewing G., Wolff H.H., Burgdorf W.H.C. Dermatologia. Italian edition edited by Carlo Gelmetti. Springer-Verlag Italia, 2002.
• Wolff K., Johnson R., Saavedra A. Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology. Italian edition of the 7th English edition, edited by Mauro Alaibac. Piccin, 2015.
• Cutaneous Lupus Erythematosus: JAMA Dermatology Patient Page
• Johns Hopkins Lupus Center: Types of Lupus
• DermNet NZ: Discoid Lupus Erythematosus
• Kuhn A, et al. “S2k guideline for treatment of cutaneous lupus erythematosus guided by the European Dermatology Forum (EDF) in cooperation with the European Academy of Dermatology and Venereology (EADV)”. Journal of the European Academy of Dermatology and Venereology. 2017;31(3):389–404.
• Okon LG, Werth VP. “Cutaneous lupus erythematosus: Diagnosis and treatment”. Best Practice & Research Clinical Rheumatology. 2013;27(3):391–404.
• American Academy of Dermatology: Lupus and Your Skin