From the Guidelines
Diagnosing cutaneous lupus requires a comprehensive approach, including clinical examination, laboratory tests, and skin biopsy, with the diagnosis often being difficult and necessitating evaluation by an experienced dermatologist and histological analysis 1. When diagnosing cutaneous lupus, it is essential to consider the various manifestations of the disease, including LE-specific (acute cutaneous LE, subacute CLE, chronic CLE, and intermittent CLE) and LE-non-specific lesions.
- The diagnosis may involve:
- Clinical examination to identify characteristic lesions such as discoid plaques, malar rash, or subacute cutaneous lupus lesions
- Laboratory tests, including antinuclear antibody (ANA), anti-double-stranded DNA, anti-Ro/SSA, and anti-La/SSB antibodies
- Skin biopsy for histological analysis, which may show interface dermatitis with lymphocytic infiltration, basement membrane thickening, and immunofluorescence revealing immune deposits at the dermal-epidermal junction
- Follow-up repeat biopsy is recommended if there is a change in the clinical morphology of the lesions or if there is a lack of response to treatment, as stated in the European League Against Rheumatism recommendations 1.
- The use of the Cutaneous Lupus Disease Area and Severity index (CLASI) in clinical practice might be considered, at least in patients with SLE with prevalent cutaneous manifestations, to assess the severity of the disease 1.
- Early diagnosis is crucial, as proper treatment can prevent scarring and progression to systemic disease in some patients.
- It is also important to perform complete blood count, comprehensive metabolic panel, and urinalysis to assess for systemic involvement.
- Diagnosis requires correlation of clinical findings with laboratory and histopathological results, as cutaneous lupus has several subtypes, including acute, subacute, and chronic forms, each with distinct presentations.
From the Research
Diagnosis of Cutaneous Lupus
- The diagnosis of cutaneous lupus erythematosus (CLE) requires a combination of physical examination, laboratory studies, histology, antibody serology, and occasionally direct immunofluorescence 2.
- The diagnosis is mainly based on the evaluation of clinical and histopathological manifestations, with an exclusion of systemic lupus erythematosus (SLE) by assessment of systemic involvement 3.
- A detailed patient's history and clinical evaluation of the skin, histopathologic and immunofluorescent examination of a skin biopsy, as well as laboratory screening are recommended 4.
Classification of Cutaneous Lupus
- Cutaneous lupus is divided into several sub-types, including acute CLE (ACLE), sub-acute CLE (SCLE), and chronic CLE (CCLE) 2.
- CCLE includes discoid lupus erythematosus (DLE), LE profundus (LEP), chilblain cutaneous lupus, and lupus tumidus 2.
- Chronic CLE can be further classified into several subclasses of lupus erythematosus (LE) such as discoid LE, verrucous LE, LE profundus, chilblain LE, and Blaschko linear LE 3.
Risk of Progression to Systemic Lupus
- Between 5 and 25% of patients with CLE can progress to SLE during the course of the disease 5.
- Common risk factors associated with SLE development include having positive anti-nuclear antibodies, hematologic abnormalities, and a higher number of lupus classification criteria at baseline 6.
- The rate of cutaneous to systemic lupus progression ranged between 0% to 42% in adult studies and 0% to 31% in pediatric groups 6.
Treatment of Cutaneous Lupus
- The treatment of cutaneous lupus consists of patient education on proper sun protection, along with appropriate topical and systemic agents 2.
- Topical corticosteroids and topical calcineurin inhibitors are first-line treatment for localized CLE lesions 3.
- Systemic treatment, including antimalarials and short-term corticosteroids, can be added for widespread or severe CLE lesions and (or) cases resistant to topical treatment 3.