Discoid Lupus of the Scalp

Overview

Discoid lupus erythematosus (DLE) of the scalp is a chronic autoimmune skin condition and one of the most common forms of cutaneous lupus. When it affects the scalp, DLE causes inflammatory, scarring plaques that permanently destroy hair follicles, resulting in irreversible scarring alopecia. The scalp is one of the most frequently involved sites in discoid lupus, and scalp involvement may occur in isolation or as part of more widespread cutaneous disease.

Discoid lupus of the scalp is more common in women than in men and can affect individuals of any age, though it most frequently presents between the ages of 20 and 45. The condition is more prevalent and tends to be more severe in individuals with darker skin phototypes. While most patients with DLE have disease confined to the skin, a minority (approximately 5 to 10 percent) may develop systemic lupus erythematosus (SLE) over time.

Causes and Risk Factors

Discoid lupus is an autoimmune condition in which the immune system inappropriately targets the skin and hair follicles, producing a characteristic interface dermatitis with inflammation at the dermal-epidermal junction. The resulting inflammatory process leads to follicular destruction, fibrosis, and permanent scarring.

Risk factors and contributing influences include:

• Ultraviolet (UV) light exposure, which is a well-established trigger and exacerbating factor for discoid lupus. Photosensitivity is a prominent feature of the disease.
• Genetic predisposition, with increased risk observed in individuals with a family history of lupus or other autoimmune conditions
• Hormonal factors, as the condition is more prevalent in women of childbearing age
• Smoking, which has been associated with increased severity and reduced treatment response in cutaneous lupus

Signs and Symptoms

Discoid lupus of the scalp presents with well-defined, coin-shaped (discoid) plaques that undergo a characteristic evolution. Clinical features include:

• Erythematous (red), scaly plaques on the scalp that may be single or multiple
• Follicular plugging, in which keratin accumulates within the dilated hair follicle openings, producing a characteristic "carpet tack" sign when scales are lifted
• Central atrophy and scarring with peripheral active inflammation, creating an expanding lesion with a scarred, smooth centre
• Dyspigmentation, with hypopigmentation in the central scarred area and hyperpigmentation at the active periphery, which is particularly prominent in darker skin
• Permanent hair loss within scarred areas, with complete destruction of hair follicles and smooth, atrophic skin replacing the normal scalp

Affected areas may be associated with itching, tenderness, or a burning sensation. Without treatment, the plaques gradually expand and coalesce, leading to increasingly extensive areas of permanent hair loss.

Diagnosis

The diagnosis of discoid lupus of the scalp is established through a combination of clinical assessment and histopathologic confirmation. A skin biopsy from an active lesion reveals characteristic features, including interface dermatitis at the dermal-epidermal junction, perivascular and periappendageal lymphocytic inflammation, basement membrane thickening, and follicular plugging. Direct immunofluorescence (DIF) testing on biopsy specimens typically demonstrates a band-like deposition of immunoglobulins and complement at the basement membrane zone (the "lupus band").

Blood tests, including antinuclear antibody (ANA) testing, complete blood count, and other lupus serologies, are performed to evaluate for the possibility of systemic lupus erythematosus. While most patients with isolated DLE have negative or low-titre ANA results, serologic screening is important for identifying the minority who may have or develop systemic disease.

Treatment Options

The primary goals of treatment for discoid lupus of the scalp are to suppress active inflammation, prevent further follicular destruction, and halt the progression of scarring alopecia. Hair loss that has already occurred due to scarring is permanent, making early and sustained treatment essential.

Prescription management of discoid lupus of the scalp includes the following approaches:

• Topical corticosteroids (high-potency) applied directly to active plaques to reduce inflammation
• Intralesional corticosteroid injections for localised, resistant plaques
• Antimalarial agents, particularly hydroxychloroquine, which is the systemic treatment of choice for cutaneous lupus and can be used long-term
• Topical calcineurin inhibitors (tacrolimus, pimecrolimus) as steroid-sparing alternatives
• Immunosuppressive agents such as mycophenolate mofetil or methotrexate for refractory cases that do not respond adequately to first-line therapies

Strict sun protection is an essential adjunctive measure for all patients with discoid lupus, as UV exposure can trigger disease flares and worsen existing lesions. Patients are advised to use broad-spectrum sunscreen, wear protective headwear, and minimize sun exposure.

When to Seek Medical Attention

Any persistent, scaly, or scarring patch on the scalp associated with hair loss should be evaluated promptly by a dermatologist. Early treatment of discoid lupus of the scalp is critical, as the inflammatory process leads to permanent follicular destruction if left unchecked. The window for preserving hair follicles narrows as the disease progresses, making timely diagnosis and intervention essential.

A referral from a family physician is typically required to access dermatology services at the Centre for Medical and Surgical Dermatology. Dr. Maksym Breslavets provides specialist evaluation and management of autoimmune hair loss conditions, including discoid lupus of the scalp.