Wong-Type Dermatomyositis Showing Porokeratosis-Like Changes (Columnar Dyskeratosis): A Case Report and Review of the Literature

Dermatomyositis (DM) is an inflammatory cutaneous and myopathic condition that classically presents in older patients with heliotrope rash, Gottron's papules, coarse erythroderma of the neck, chest and shoulders, and proximal muscle weakness that can signal the presence of an underlying malignancy in a minority [1]. A unique variant of DM known as Wong-type DM describes the superimposition of the clinical and histopathologic features of pityriasis rubra pilaris (PRP) onto DM. Wong-type DM is named after K.O. Wong, who reported a series of 23 DM patients, 11 of whom had hyperkeratotic follicular papules [2]. Herein, we review the literature [2,3,4,5,6,7,8,9,10,11,12,13,14,15] and report an additional case of Wong-type DM with coexisting clinicopathologic features that mimicked porokeratosis.

A 50-year-old woman with insulin-dependent diabetes presented to the dermatology department with a scaly, itchy rash on her arms and back that spread to her face, scalp, and then to most of her body. She also had a periorbital heliotrope rash and flat, scaly, pink papules on the dorsum of both hands with mild eponychial inflammation. There were no complaints or signs of muscle weakness. Topical corticosteroid therapy was prescribed. Nine months later, her rash progressed with the development of confluent hyperkeratotic patches and papules of itchy, coarse, dirty grayish, dry skin with areas of dull-pink coloration. In addition to generalized hyperkeratosis, scattered hypopigmented macules and papules with a rim of fine scaling on both forearms was apparent. Sharply demarcated skip areas were present around her waist and medial and inferior breasts, as well as on the sides of her hands and feet. The heliotrope rash had resolved, but Gottron's papules had persisted (fig. 1). Dry, coarse skin on the sides of the face and scalp with dyschromia, as well as patchy, nonscarring alopecia, were present. She reported new sequelae of transient ‘swelling' of varied areas of the skin, ‘stiffness' in her hips, and difficulties ‘hitting the high notes' while recreationally singing (dysphonia). She denied any other symptoms such as muscle weakness. On physical examination, the patient was a well-appearing, obese woman in no acute distress. Her vitals were all within normal limits. There was no lymphadenopathy. Her muscle strength was 5/5, her range of motion intact, and there was no joint or muscle pain or tenderness upon palpation. Serology was significant only for positive ANA and mildly elevated glucose. The rest of the chemistry panel, thyroid-stimulating hormone, aldolase, creatine kinase, and complete blood count were normal. In addition to insulin-dependent diabetes with use of the insulin pump, her previous medical history included obesity, hyperlipidemia, hypothyroidism, asthma, and seasonal allergies, managed by an HMG-CoA reductase inhibitor, levothyroxine, albuterol inhaler, and cetirizine, respectively. She had had a carpal tunnel repair many years previously.

A punch biopsy performed at first presentation showed a subtle, cell-poor, vacuolar interface dermatitis with rare melanophages consistent with DM, and a focus of suppurative folliculitis, the latter of which was interpreted to represent an incidental process. Punch biopsies taken after the rash had progressed showed more severe alterations compared to the first biopsy. Specifically, the dominant changes consisted of lymphocytic vacuolar interface dermatitis with effacement of some rete ridges, clusters of necrotic keratinocytes, and numerous melanophages and free melanin found at the dermal-epidermal junction and papillary dermis. In addition, extensive dermal mucin deposition was evident. In addition, irregular psoriasiform hyperplasia, alternating mounds of para- and orthokeratosis, and follicular plugging were superimposed on the interface alterations. No basement membrane thickening or dermal infiltrates of neutrophils and/or eosinophils were identified (fig. 2). Biopsy of the papules with fine collarettes of scale showed discontinuous vertical tiers of dyskeratotic cells admixed with parakeratotic cells associated with underlying focal hypogranulosis, vacuolar interface alterations and degenerated keratinocytes. This constellation of histopathologic findings resembles those described for columnar dyskeratosis (fig. 3) [16]. Direct immunofluorescence studies demonstrated C3 superficial vascular deposits, trace basement membrane IgM deposits, and numerous colloid bodies - changes that can be found in DM [15].

Initial treatment with oral prednisone was discontinued due to exacerbation of her diabetes. In place of corticosteroid therapy, alternating 25/35 mg Soriatane daily resulted in a marked diminishment of the hyperkeratotic papules. However, her skin remained hyperpigmented in the affected regions. After 22 months of follow-up, she is stable without renewed onset of cutaneous or muscular symptoms.

A systematic review of the literature revealed 25 cases of Wong-type DM since 1956 [2,3,4,5,6,7,8,9,10,11,12,13,14,15]. The average age at presentation was 40 years, with a median age of 46 years and a range from 9 to 89 years. The sex ratio (M:F) was 1:2.5, illustrating that the most commonly affected population is middle-aged women. Two patients had a history of eczema/atopic dermatitis [5,6], and 1 patient had preexisting chronic myelogenous leukemia in remission [15]. Presenting symptoms included a rash (100%), muscle weakness (large muscles 92%, dysphagia/dysphonia >20%), and fatigue/flu-like illness (33%). Signs included an erythematous hyperkeratotic eruption (100%), heliotrope rash (88%), Gottron's papules (64%), and palmar-plantar keratoderma (36%). The order of onset of PRP was varied, with no pattern significantly dominating: 6 cases developed signs of PRP before DM, 4 cases showed DM before PRP, and 3 cases had a simultaneous onset of PRP and DM. Histopathology showed follicular hyperkeratosis (76%), vacuolar interface dermatitis (72%), hyperkeratosis composed of alternating areas of ortho- and parakeratosis arranged in both horizontal and vertical directions (25%), dermal mucin deposition (16%), and arrector pili myositis (16%). No basement membrane thickening or coexisting neutrophilic infiltrate has been described. However, rare eosinophils were found in the lesional skin of a 54-year-old man with Wong-type DM associated with anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibodies [14]. All muscle biopsies performed showed perifascicular atrophy and perivascular inflammation. Serology showed elevated muscle enzymes (creatine phosphokinase > aldolase > LDH, ALT; 91%), positive ANA (36%), and autoantibodies (anti-smith, anti-DNA, and anti-MDA5; 18%). When performed, all EMG results were consistent with inflammatory myositis.

Treatment consisted of systemic corticosteroids, antimalarials (hydroquinone), and/or cytotoxic agents (methotrexate, azathioprine, or mycophenolate mofetil), alone or in combination: corticosteroids alone (60%), in combination with immunosuppressant lesions (28%), or hydroquinone (4%). No reports of retinoid therapy exist. The outcomes were full resolution of cutaneous and muscular disease (64%), cutaneous resolution only (7%), and cutaneous and muscle improvement but not resolution (14%); the remainder of patients was lost to follow-up (15%). The average follow-up time was 45 months (range 8-168). In none of the patients, an underlying malignancy was discovered during their disease course.

The literature revealed only 1 other case of Wong-type DM with porokeratosis-like lesions, in a 53-year-old woman reported by Lupton et al. [9]. Other similarities to our case included dysphonia and positive ANA with the absence of any autoantibodies (Scl-70, SS-A, SS-B, anti-Jo1, anti-RNP, anti-smith, and anti-DNA). In contrast, Lupton's case presented with PRP and then developed DM with porokeratosis-like lesions, whereas our patient first presented with signs of DM. Moreover, Lupton's patient suffered systemic symptoms (weight loss, difficulty sleeping), displayed severe muscle weakness, reported at one point the inability to sit upright on her own, and had elevated aldolase and creatine kinase. While our patient had several chronic diseases, there was no apparent correlation to her rash, and after nearly 2 years of follow-up, she still lacked any significant muscle weakness. Lupton described the lesions as ‘porokeratosis-like', without providing any clinical photographs. The histology was described as a ‘pseudo-cornoid lamella with focal loss of the granular layer with overlying column of parakeratotic cells in delled epidermis' [9]. This photomicrograph also shows dyskeratotic rather than parakeratotic cells, which is similar to the findings in our patient. Lastly, our patient is doing well off of retinoid therapy, whereas the DM in Lupton's patient is maintained on low-dose prednisone and weekly oral methotrexate as she cannot tolerate lower doses.

The dynamic, diverse clinical and histological features described above illuminate the singularity of Wong-type DM. It is a diagnostic challenge if one is not aware of this hybrid disease, which depending on its onset, could be labeled as DM or PRP. Both conditions alone have been associated with underlying malignancy and immunosuppression [2,17,18]. Porokeratosis is also associated with decreased immune surveillance and systemic diseases [19]. However, based on the literature review, Wong-type DM lacks an association with malignancy or cause of immune suppression, even if the short duration of follow-up, the relatively low number of reported cases, and the young age at presentation warrants a malignancy work-up. Nonetheless, Wong-type DM resolved in most cases, suggesting a short-lived trigger and/or cause.

The most unique feature seen in this case was the development of several regions of grouped macules and papules showing a collarette of scale that histopathologically corresponded to irregular vertical columns of dyskeratotic cells within epidermal dells. These structures represented pseudocornoid lamellae. A typical cornoid lamella exhibits a diagonally oriented column of tightly fitted parakeratotic cells. The vertical columns of mostly dyskeratotic rather than parakeratotic cells reported herein most closely resemble the recently described, putative keratinization disorder termed ‘columnar dyskeratosis' [16]. The 2 patients described in this case report presented with widespread verrucous, red-brown plaques; only one of them demonstrated clinical findings suggestive of porokeratosis: a fine scale on the palms of an organ transplant recipient. The other patient did not use immunosuppressants; thus, an immune surveillance problem was discounted. A drug etiology (from atorvastatin) was considered; however, no reports of a similar eruption have been documented [16]. The fact that 2 patients presented with identical histopathologic findings suggests a unique reaction pattern, if not a clinicopathologic entity that is a manifestation of cutaneous stress and the skin's attempt to maintain homeostasis [20]. Overall, columnar dyskeratosis is the best, most apt histopathologic description of this unique pattern of dyskeratosis.

In conclusion, for patients with signs of DM and PRP, the diagnosis of Wong-type DM should be considered, and prompt treatment should be started, with regular follow-up to find an individualized, effective regimen. The addition of porokeratosis-like changes is also an exceptional characteristic of Wong-type DM. The pathogenesis and clinical significance of this particular phenomenon of columnar dyskeratosis requires further elucidation. Therefore, we urge physicians to search for these alterations in patients with DM to determine disease associations and prognostic significance.

This case study was supported in part by clinical revenues and generous donations to the Divisions of Dermatology and Dermatopathology, Department of Pathology, Albany Medical College.

The authors declare no conflicts of interest.