Zebra Stripes in Dermatomyositis: Case Report and Review of Flagellate Erythema‐Associated Dermatomyositis

Editor Flagellate erythema presents with characteristic linear wheal-like manifestations, and has been associated with chemotherapy, toxins, and rheumatologic diseases. Here, we describe a case of dermatomyositis-associated flagellate erythema with discussion and review of cases described in the literature. A 57-year-old healthy woman presented for a 9-month history of ‘red welts’ on her back. Ten months prior, she developed a ‘red rash’ on her left eyebrow and left collarbone, which spread to her face, arms, and forehead, and worsened with sun exposure. Physical examination revealed erythematous linear flagellate patches and plaques on the back (sparing the mid upper region) (Fig. 1a), thin violaceous to pink papules over the metacarpal–phalangeal joints (Gottron’s papules) (Fig. 1b), pink patches at the elbow joints (Gottron’s sign), ragged cuticles, periungual dilated capillaries with areas of dropout (Fig. 1c), fine scalp scale, violaceous scaly patches of the lateral thighs (Holster sign), as well as erythema and poikiloderma on the face, ears, chest, and abdomen. There was no dermatographism or oral ulceration. Proximal muscle strength was full. A skin biopsy of the upper back showed lymphocytic inflammation along the dermal–epidermal junction associated with focal vacuolar degeneration and necrotic keratinocytes at the basal layer. Pigmented melanophages were seen in the upper portions of the dermis. Antinuclear antibodies (by direct fluorescent antibody) were weakly positive in a speckled pattern (titer 1 : 80). Tests for other rheumatologic antibodies were negative (Table 1). Correlation of the clinical and laboratory findings established the diagnosis of amyopathic dermatomyositis with flagellate erythema. Epidemiologically present in 5% of patients with dermatomyositis, flagellate erythema represents an active disease state with exam findings mirroring disease severity. In the cases of dermatomyositis-associated flagellate erythema described, classic features such as heliotrope erythema and Gottron’s papules were present in all cases except one. A total of 60% of cases (9/15) were seen in males, while the ages of females and males exhibit a similar distribution (Table 1). To date, only one case of juvenile dermatomyositis has been described in association with flagellate erythema. While pruritus was reported in 20% (3/15) of cases, none of the cases exhibited features of dermatographism (Table 1). To date, three cases (3/15, 20%) of flagellate erythemaassociated amyopathic dermatomyositis have been described in the literature, although two other cases (2/15, 13%), including our current case, may represent clinically amyopathic dermatomyositis (CADM) (Table 1). Two of the three amyopathic patients tested positive for antimelanoma differentiation-associated protein 5 (CADM-140) and antitranscriptional intermediary factor 1 gamma (TIF-1c), respectively. Pulmonary complications, such as interstitial lung disease, are reported in 10–40% of patients, and can be seen in up to 70% of patients with antihistidyl transfer RNA synthetase (Jo-1) or CADM-140 antibodies. In our present review, 20% (3/15) of cases were complicated by lung disease, one of these cases exhibited CADM-140 + dermatomyositis. Only one case in the literature that was complicated by interstitial pneumonitis failed to respond to treatment. Interestingly, the risk of malignancy is increased during the first 3–5 years after dermatomyositis onset with a reported frequency of 9–32%. In our review, 40% (6/15) of cases had concurrent malignancies (Table 1), which may be slightly higher than the reported frequency of malignancy in dermatomyositis. Of note, five of the six patients with a malignancy were male. Also, all three cases of amyopathic dermatomyositis presented with concurrent malignancies. Furthermore, these findings suggest that flagellate erythema, especially when seen in male patients, may be a risk factor for malignancy. Further studies will better elucidate the relationship between flagellate erythema and malignancy in these patients. (a) (b) (c)