Beyond the surface: dermoscopic revelations in clofazimine pigmentation

Dear Editor, Clofazimine is a weakly basic antibiotic licensed by the Food and Drug Administration to treat leprosy and multidrug-resistant tuberculosis. After a long course of treatment, clofazimine precipitates and bioaccumulates widely throughout the body to create crystal-like drug inclusions. The most prevalent side effect of clofazimine is thought to be skin pigmentation, which is thought to be caused by the drug’s red hue [1]. A 52-year-old female diagnosed with borderline lepromatous Hansen’s disease presented with brownish hyperpigmentation on the face (Fig. 1a) and forearm (Fig. 2a) for 2 months. She was started on multibacillary multidrug therapy of oral rifampicin, clofazimine, and dapsone 8 months ago. After obtaining the patient’s consent, histopathology from the affected patch on the forearm was done, which revealed perivascular lymphohistiocytic infiltration and fine and coarse brown granular pigment within macrophages (Fig. 3). Dermoscopic examination of the face (Fig. 1b) revealed perifollicular hypopigmentation with an orange hue, as well as an accentuation of the pseudoreticular pattern. The forearm (Fig. 2b) showed skin furrow sparing with accentuation of reticular brown pigment, diffuse homogeneous background brown pigmentation, an orange hue, and a honeycomb pattern. The patient was diagnosed with clofazimine-induced hyperpigmentation.Figure 1: (a) Hyperpigmentation on the face. (b) Dermoscopy of the face (Dermlite, DL5, ×10, polarized mode) demonstrates perifollicular hypopigmentation with an orange hue and accentuation of the pseudoreticular pattern.Figure 2: (a) Hyperpigmentation on the forearm. (b) Dermoscopy of the forearm (Dermlite, DL5, ×10, polarized mode) demonstrates skin furrow sparing with accentuation of reticular brown pigment, diffuse homogeneous background brown pigmentation, an orange hue, and a honeycomb pattern.Figure 3: Histopathology shows perivascular lymphohistiocytic infiltration and fine and coarse brown granular pigment within macrophages (H and E, ×40).Leprosy is an infectious granulomatous disease which, on dermoscopy, reveals the presence of structureless orange to yellowish patches that can be dispersed in a diffuse or localized pattern. The drug clofazimine is a lipophilic phenazine antibiotic that is weakly basic and frequently induces reddish-pink discoloration of the skin [2]. The features of dermoscopic examination of clofazimine-induced hyperpigmentation show a honeycomb pattern with yellowish-white globules interspersed along a black background [3]. Differential diagnosis includes other granulomatous conditions like cutaneous leishmaniasis, sarcoidosis, lupus vulgaris, and lichen planus pigmentosus [4]. Dermoscopy of the lesions allows us to distinguish between drug-induced hyperpigmentation and lepra reactions and facilitates assessment of patient compliance with treatment. Acknowledgements Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.