Acta Dermato-Venereologica 98-10CompleteContent | Page 14

975 SHORT COMMUNICATION A Case of Pityriasis Rubra Pilaris Treated Successfully with the Phosphodiesterase-4 Inhibitor Apremilast Maria CHO 1 , Tetsuya HONDA 1 *, Chiyuki UESHIMA 2 , Tatsuki KATAOKA 2 , Atsushi OTSUKA 1 and Kenji KABASHIMA 1 1 Department of Dermatology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara, Sakyo, Kyoto 606-8507, and 2 Department of Diagnostic Pathology, Kyoto University Hospital, Kyoto, Japan. *E-mail: [email protected] Accepted Jun 14, 2018; Epub ahead of print Jun 25, 2018 Pityriasis rubra pilaris (PRP) is an inflammatory skin condition characterized by well-circumscribed hyperke- ratotic plaques and palmoplantar keratoderma (1). The aetiology of PRP is unclear and although various treat- ment options, such as topical steroids and oral retinoic acids, are available, treatment responses are inconsistent and management is often difficult (2). We report here a case of PRP that was treated successfully with apremilast, a phosphodiesterase-4 (PDE4) inhibitor. Furthermore, using immunohistochemistry we examined the expres- sion of nuclear factor of kappa light chain enhancer in B cells (NF-κB) and caspase recruitment domain family, member 14 (CARD14), a molecule that induces acti- vation of NF-κB and is reported to be involved in the pathogenesis of PRP in the skin. CASE REPORT A 60-year-old woman with no significant medical or family history attended our clinic 4 years ago with a 1-month history of well-demarcated, pruritic erythema keratodes on the hands, soles of the feet, elbows, and knees (Fig. 1a). Keratinizing papules on the palms, and scales on the dorsa of the hands and nail beds, were also seen. No nail-fold capillary abnormalities or nail changes were evident, and she had no systemic symptoms. Skin biopsy at initial presentation showed a “chequerboard pattern” of alternating parakeratosis and orthokerato- sis, irregularly elongated rete ridges, acantholysis, and dermal melanin incontinence (Fig. 2a). Based on the clinical and histological findings, she was diagnosed with type I PRP. She developed mild arthralgia 5 months later and was referred to the rheumatology department. Fig. 1. Clinical presentation of pityriasis rubra pilaris before and after treatment with apremilast. (a) Keratinization and erythema were seen on both feet and knees at initial presentation. (b) Significant improvements in the skin lesions were seen at 6 months after the start of treatment with apremilast. Her autoantibody screening showed an elevated anti- centromere antibody and limited cutaneous systemic sclerosis was diagnosed, but no additional treatments were started by the rheumatologists. Over the following 4 years all strengths of topical steroid ointments, topical vitamin D 3 analogues and salicylic acid, oral retinoic acid, and phototherapy were tried. Other treatments, such as methotrexate, were not considered due to pos- sible side-effects. Although mild improvements were seen throughout the treatment period, the skin lesions always recurred and never completely resolved. As the symptoms were refractory, our treatment options were limited and we decided to start apremilast at 30 mg/day. Although no substantial changes in the hyperkeratosis of the feet were seen one month after the introduction of apremilast, significant improvements were seen after 2 months. Currently, the skin lesions have not shown any Fig. 2. Histological presentation and immunohistochemical staining of pityriasis rubra pilaris for p65 and CARD14. (a) Haematoxylin and eosin staining of the skin biopsy shows the classic “chequerboard appearance” of alternating parakeratosis and orthokeratosis (original magnification ×5; scale bar=500 mm). (b) Skin biopsy stained for p65 shows nuclear staining in keratinocytes (white circle) and in inflammatory cells surrounding the vasculature (black square). (original magnification ×10; scale bar=250 mm). (c) Skin biopsy stained for CARD14. Weak expressions of CARD14 were seen in keratinocytes (white circle) and in dermal inflammatory cells around vessels (black square) (original magnification ×10; scale bar=250 mm). This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2018 Acta Dermato-Venereologica. doi: 10.2340/00015555-2995 Acta Derm Venereol 2018; 98: 975–976