A 36-year-old African American woman presents with a three-day history of mildly painful pruritic skin lesions. She denies fever, chills, headache, trauma, recent foreign travel, new environmental exposures, unintended weight loss, or night sweats. Her past medical history is significant only for lupus.
What is the name of this cutaneous condition, and how would you manage it in the emergency department?
Diagnosis: Discoid Lupus Erythematosus
Systemic lupus erythematosus (SLE) is a potentially debilitating and life-threatening autoimmune disease that can affect nearly every organ system in the body. Yet no definitive treatment or cure currently exists. More than 1.5 million Americans have some form of lupus, with 90 percent of cases in women. Lupus is two to three times more common among African Americans, Hispanics, Native Americans, and Asians. And for unknown reasons, African American and Hispanic women typically develop symptoms at an earlier age and have a worse prognosis. (Lupus 2006;15:715.)
Lupus is often difficult to diagnose, and delayed diagnosis is common. Because of the various clinical manifestations of SLE, the emergency physician should be familiar with the common and life-threatening disease presentations. More than 80 percent of patients with SLE have skin and mucous membrane involvement at some time during their disease progression. The list of possible cutaneous lesions is extensive, varying from the classic malar butterfly rash to bullae, alopecia, urticaria, ulcerations, or numerous vasculitis- and vaculopathy-associated conditions. (Clin Dermatol 2006;24: 348.)
It is not uncommon for an SLE patient to be afflicted with more than one skin disease. Some forms of lupus-associated skin conditions are photosensitive, and if advanced or severe can lead to permanent scarring. Discoid lesions are not pathognomonic for lupus, but are found in nearly 25 percent of SLE patients. Less than 10 percent of patients with discoid lesions go on to develop lupus, but if they do, these patients tend to have a mild form of SLE. Discoid lupus (also known as chronic cutaneous lupus) is three times more common in women, as opposed to SLE, which is 10 times more common.
Discoid lupus is a chronic inflammatory condition that often leads to scarring, with an unfortunate predilection for the face. Discoid lesions are classically erythematous circumscribed plaques with central hypopigmentation and an adherent crusty scale that can be painful or mildly pruritic. These typically form on the face, ears, scalp, and neck. Mucous membranes, including the lips, may be involved. (Clin Dermatol 2004;22:121.) During exacerbations, the periphery of the lesions tends to have active inflammation, which eventually heals leaving a hyper- or hypopigmented centrally depressed scar, telangiectasias, and follicular plugging (dilated hair follicles). Because discoid lesions are scaling plaques, and at times hyperkeratotic in appearance, they are commonly misdiagnosed as psoriasis, eczema, warts, syphilis, squamous cell cancer, actinic keratosis (pre-malignant), keratoacanthoma, dermatomyositis, rosacea, hypertrophic lichen planus (mildly pruritic), and prurigo nodularis (intensely pruritic). Other conditions that mimic discoid lupus are sarcoidosis, cutaneous tuberculosis (Lupus vulgaris), tinea, and polymorphous light eruption. Malignant degeneration of discoid lesions can rarely occur, and should be considered. During a cutaneous discoid exacerbation, less than five percent of patients have associated systemic involvement.
Discoid lupus is an autoimmune phenomenon. The precise etiology is unknown, but is clearly multifactorial including genetic, environmental, and hormonal components. The etiology of the disease manifestations, however, is typically the result of destructive immunocomplex deposition. (Curr Dir Autoimmun 2008;10:119.)
Control of a discoid eruption is desirable because it can lead to permanent scarring and alopecia. Patients presenting with new onset discoid lesions need a referral for an outpatient workup that typically includes a skin biopsy and testing for the presence of antinuclear antibody test (ANA), anti-Ro, anti-double stranded DNA, anti-Smith antibodies, and rheumatoid factor. Emergency physicians should screen for other lupus-associated conditions as warranted by the patient's history and condition.
Some lesions are photosensitive, and can exacerbate inflammation and subsequent scarring and alopecia, which in turn can lead to unacceptable cosmetic results. Patients should be counseled to wear sun-blocking clothes and UVA/UVB sunscreen daily. Topical glucocorticoids are typically first-line treatment for mild cutaneous exacerbations. More severe exacerbations may require more potent topical steroid agents than hydrocortisone (e.g., fluorinated steroids). These agents, unfortunately, are known to cause hypopigmentation, alopecia, telangiectasias, and skin thinning with prolonged or repeat use. Different strengths and formulations are recommended depending on the site (e.g., lotion or foam for scalp), extent of involvement, and history of previous treatment regimens. There also may be some role for intralesion steroid injections, but this is not within the purview of the emergency physician. Other topical agents, including the immunosuppressants tacrolimus and pimecrolimus, and topical retinoids may be beneficial, but more research is needed before they are considered a mainstay of treatment.
Antimalarial agents including hydroxychloroquine (Plaquenil), chloroquine (Aralen), and quinacrine are effective in treating severe reactions, but typically require weeks of prolonged treatment and can have deleterious side effects. Smoking appears to decrease the effectiveness of these medications, and smoking cessation is recommended during treatment.
Other oral agents that are infrequently used for discoid lupus exacerbations, refractory to the treatments mentioned above, include systemic glucocorticoids, oral retinoids, immunomodulators (e.g., cyclosporine, methotrexate, azathioprine), gold, Dapsone, thalidomide, sulfasalazine, IVIG, and phenytoin. (Cochrane Database Syst Rev 2009; Oct 7 :CD002954.) Laser therapy and excision are also options.
Given that varying treatment options for discoid lupus exist, with potentially harmful side effects and typically the need for long-term management, treatment initiated in the ED should be done in consultation with a discoid lupus specialist. For patients on long-term antimalarial treatment, ophthalmology referral is recommended to monitor for retinopathy. Patients with SLE also may require internal medicine, nephrology, cardiology, or pulmonary input, depending on their comorbid lupus disorders.
In addition to the cutaneous discoid exacerbation, this patient had systemic lupus symptoms, and was admitted for rheumatology evaluation.