122 EJD, vol. 24, n ◦ 1, January-February 2014 1 Department of Environmental Immuno-Dermatology, Yokohama City School of Medicine, Fukuura 3-9, Kanazawa, Yokohama, 236-0004, Japan 2 Department of Dermatology, International University of Health and Welfare, Atami, Japan <fuji_fuji_fuji_0101@yahoo.co.jp> Hiroyuki FUJITA 1 Mayumi NAGASHIMA 1 Yoshihiro TAKESHITA 2 Michiko AIHARA 1 1. Kabashima K. New concept of the pathogenesis of atopic dermati- tis: interplay among the barrier, allergy, and pruritus as a trinity.J Dermatol Sci 2013; 70: 3-11. 2. Bender BG, Ballard R, Canono B, Murphy JR, Leung DY. Disease severity, scratching, and sleep quality in patients with atopic dermatitis. J Am Acad Dermatol 2008; 58: 415-20. 3. Bender BG, Leung SB, Leung DY. Actigraphy assessment of sleep disturbance in patients with atopic dermatitis: an objective life quality measure. J Allergy Clin Immunol 2003; 111: 598-602. 4. Murray CS, Rees JL. Are subjective accounts of itch to be relied on? The lack of relation between visual analogue itch scores and actigraphic measures of scratch. Acta Derm Venereol 2011; 91: 18-23. 5. Bringhurst C, Waterston K, Schofield O, Benjamin K, Rees JL. Mea- surement of itch using actigraphy in pediatric and adult populations.J Am Acad Dermatol 2004; 51: 893-8. 6. Saeki H, Tamaki K. Thymus and activation regulated chemokine (TARC)/CCL17 and skin diseases. J Dermatol Sci 2006; 43: 75-84. 7. Ebata T, Iwasaki S, Kamide R, Niimura M. Use of a wrist activity monitor for the measurement of nocturnal scratching in patients with atopic dermatitis. Br J Dermatol 2001; 144: 305-9. doi:10.1684/ejd.2013.2242 Pachyonychia congenita in Japan: report of familial cases with a recurrent KRT16 mutation Pachyonychia congenita (PC) is a rare autosomal dominant keratinizing disorder showing nail changes. Besides hyper- trophic nail dystrophy, the main clinical features include painful and highly debilitating plantar keratoderma, oral leukokeratosis and a variety of epidermal cysts. Classi- cally, PC is classified into type 1 (PC-1) and type 2 (PC-2), depending on the distinct sets of clinical symptoms, pri- marily on the absence and presence of pilosebaceous cysts, respectively [1]. Since the causative genetic mutations were successively identified in four Keratin (KRT) genes in the mid 1990s, PC has been defined as the keratin disorder at the molecular level [2-4]. In correlation with the classical classification, mutations in the KRT6A or KRT16 gene and those in the KRT6B or KRT17 gene have been identified in PC-1 and PC-2, respectively. A 32-year-old Japanese woman showing callus-like, painful, hyperkeratotic lesions on the soles was referred to our hospital in August 2011. She had repeatedly deve- loped blistering on the soles after walking since 4 years of age, and the lesions gradually grew into the callus-like hyperkeratotic lesions. As her first son developed slightly hyperkeratotic lesions on the hands and feet after begin- C T C C T C A A T A A/G T G A C G A C Leu124 Asn125 Asp126 Control Patient p.Asn125Ser A B C D E G F Figure 1. Clinical features of the proband (A-E) and her son (F), with the genetic feature (G). A) Symmetrical plantar kera- toderma. B) Thick toenails with focal keratoderma. C) A pair of hand-made sandals adjusted for the focal keratoderma. D) Mild changes on the fingernails. E) Leukokeratosis of the tongue. F) Thick toenails. G) Electropherograms obtained by sequencing the KRT16 gene for the genomic DNA samples from a control (left) and the proband (right). ning walking, she consulted a dermatologist and then was referred to us. None of her relatives, except for her son, showed any similar symptoms. A physical examination revealed severe, callus-like, yellowish, symmetrical, hyper- keratotic lesions, mainly on the heels and the frontal areas of the soles, as well as the internal side of the first toes, the second and third digital pads and the tip of the fourth toes (figure 1A). Thickening and deformity of the first and the fourth toenails were also seen (figure 1B). To reduce the plantar pain, she used a pair of hand-made sandals whose soles were adjusted to reduce the pressure of the focal hyperkeratotic lesions (figure 1C). Although there were no hyperkeratotic lesions in the palms, hyperkera-