INTRODUCTION
Discoid lupus erythematosus (DLE) is a subtype of lupus erythematosus which presents mainly in areas above the neck include the nose, malar region, and ears.1 It is characterized clinically by round demarcated lesions with varying degrees of erythema, telangiectasia, scaling, follicular plugging, dyspigmentation, atrophy, and scarring.2 While clinical
presentation is usually distinctive enough to diagnose DLE, histopathological samples may be needed to differentiate it from chronic eczema, toxicity reactions from prior treatment, sarcoidosis, light eruptions, lymphomas and pseudolymphomas,
and postinflammatory hyperpigmentation.1,2
An alternative to the traditional biopsy for the confirmation of a DLE diagnosis is reflectance confocal microscopy (RCM), a noninvasive imaging tool that uses infrared light to illuminate the underlying skin and reflects these images back through an aperture, which then allows for the assembly of black and white images in a confocal plane.3 The white contrast is provided by various highly refractive structures such as melanin, inflammatory
cells, and other skin structures.4,5 Optically layered sections of the skin down to the level of 300 μm or the superficial dermis
can be captured by RCM. Reflectance confocal microscopy provides a 3-dimensional view of the imaged lesion through horizontal plane imaging, which provides a section similar to histology and the vertical plane imaging.6
CASE SERIES
Case 1
A 47 year-old African-American female presented with a hyper-pigmented, erythematous plaque on her right cheek (figure 1) for which the differential diagnosis clinically was DLE vs post-inflammatory
hyperpigmentation. The lesion on RCM (Vivascope 1500, Lucid Inc., Rochester, NY) showed features consistent with DLE including inflammatory cells, (Figure 2), inflammation at the dermo-epidermal junctions (Figure 3), and vacuolar degeneration
(Figures 4 and 5), a biopsy from the lesion revealed areas of vacuolar degeneration and pigment incontinence consistent
with the RCM diagnosis of DLE (Figure 6).
Case 2
A 50 year-old female patient with history of DLE diagnosed in 2009 presented in July 2011 with a 15-mm irregularly shaped plaque on her right lateral cheek. Her initial diagnosis of DLE in 2009 had been made from a papule on her nose; she also presented at the time with patchy alopecia and a lesion on her scalp. After a year-long treatment regimen of topical steroids and other care for DLE such as avoiding the sun and using sunscreen, her lesions were healed. Prior to biopsy of her new lesion in July 2011, the lesion was imaged with RCM. Areas of vacuolar degeneration with inflammation at dermo-epidermal junction (Figure 7) were observed in the RCM images. Biopsy of this new lesion confirmed the clinical and RCM diagnoses
