Reticulate Acropigmentation Of Kitamura Research Articles

Inherited Reticulate Pigmentary Disorders.

Reticulate pigmentary disorders (RPDs) are a group of inherited and acquired skin conditions characterized by hyperpigmented and/or hypopigmented macules. Inherited RPDs include dyschromatosis symmetrica hereditaria (DSH), dyschromatosis universalis hereditaria (DUH), reticulate acropigmentation of Kitamura (RAK), Dowling-Degos disease (DDD), dyskeratosis congenita (DKC), Naegeli-Franceschetti-Jadassohn syndrome (NFJS), dermatopathia pigmentosa reticularis (DPR), and X-linked reticulate pigmentary disorder. Although reticulate pattern of pigmentation is a common characteristic of this spectrum of disorders, the distribution of pigmentation varies among these disorders, and there may be clinical manifestations beyond pigmentation. DSH, DUH, and RAK are mostly reported in East Asian ethnicities. DDD is more common in Caucasians, although it is also reported in Asian countries. Other RPDs show no racial predilection. This article reviews the clinical, histological, and genetic variations of inherited RPDs.

Reticulate Acropigmentation of Kitamura: A Dermoscopic Perspective.

Reticulate Acropigmentation of Kitamura: A Dermoscopic Perspective.

Unilateral reticulate pigmentation of Kitamura

Reticulate acropigmentation of Kitamura (RAPK) is a rare genodermatosis characterized by pigmented, angulated, atrophic freckle-like lesions arranged in a reticulate pattern on the dorsal surface of hands and feet with symmetric involvement. We hereby report a case of unilateral RAPK in a 29-year-old female. The patient had cutaneous lesions and histopathology characteristic of RAPK, involving only the left side of her body with clear midline demarcation. This case is being reported in view of its rarity and being the first of its kind.

A Case of Reticulate Acropigmentation of Kitamura Treated with 532-nm Q-Switched Nd:YAG Laser: 10 Years of Follow-Up Observation.

Dear Editor: Reticulate acropigmentation of Kitamura (RAPK) is an uncommon pigmentary disorder that was first reported in Japan1. Since then, similar cases have been described worldwide; nevertheless, most were still in Japanese patients2. RAPK shows reticulate hyperpigmentation of the dorsum of the acral areas without hypopigmented macules. Despite the report of using 20% azelaic acid to treat RAPK, there has been no certain treatment guaranteeing a clinical effect for more than half a century3. Herein, we present a patient with RAPK who was successfully treated with 532-nm Q-switched Nd:YAG laser (532-nm QSND; MedLite IV Nd:YAG laser; HOYA ConBio, Fremont, CA, USA). A 29-year-old Korean woman visited our dermatologic clinic for childhood-onset acral hyperpigmentation in March 2002. Reticulate acral hyperpigmentation was recognized but no interspersed hypopigmentation was detected. She had no family history of pigmentary disorder. She neither had taken medication known to induce hyperpigmentation nor had a history of contact to any chemical agent that can cause pigmentary changes. She underwent skin biopsies for the hyperpigmented confluent patch on the dorsum of the hand and discrete hyperpigmented macule on the dorsum of the foot. Histologically, lentiginous melanocytic hyperplasia and some dermal melanophages were observed with mild epidermal atrophy (Fig. 1). On the basis of the findings, we made a diagnosis of RAPK. Considering the histologic findings of superficially situated melanocytic hyperplasia, we used 532-nm QSND. We tested the laser to evaluate its efficacy and safety. A small area of the left arm was selected as the test area. Topical anesthetic agent was applied on the area before treatment. Treatment with parameters of 4-mm spot size, 2 J/cm2 was applied. Some pain was present during treatment but it was tolerable, and significant clinical improvement was observed in the area without any complication. We gradually expanded the treatment area. During the sessions, mild blisters developed after treatment with 2.7 J/cm2 or higher; however, they disappeared without leaving hyper- or hypopigmentation. A total of seven sessions of laser treatment, with energy between 2.0 and 2.7 J/cm2, were successfully made from March 2002 to November 2007 (Fig. 2), and the interval between treatments was several months to 2 years. Thereafter, she was lost to follow-up for 4 years because of personal reasons. In March 2012, she visited our clinic for treatment of the remaining lesions. There was neither a recurrence of RAPK nor treatment-related adverse effects on the previously treated area. We treated the residual lesions with same parameters as previously used, and the clinical effect was also good. Fig. 1 (A) Lentiginous melanocytic hyperplasia and dermal melanophages with some degree of epidermal atrophy (H&E, ×100). (B) Lentiginous hyperplasia of the basal melanocytes (Fontana Masson, ×100). Fig. 2 (A) Reticulated brownish patches on the dorsum of both hands before treatment. (B) Significant improvement of hyperpigmentation after seven sessions of treatment. (C) Clinical improvement was maintained after 4 years without treatment. (D) Significant ... Recently, Fahad et al.4 introduced the use of 755-nm Q-switched alexandrite laser as an effective modality to treat RAPK. In our case, the successful depigmentation with 532-nm QSND was made without a significant adverse reaction. We also observed the maintenance of clinical improvement for 10 years without any repigmentation on the treated area. Thus, 532-nm QSND may play a central role in the treatment of RAPK. As this is a single case of clinical experience, a follow-up study will be needed.

A case of reticulate acropigmentation of kitamura: dowling degos disease overlap with unusual clinical manifestations.

Reticulate hyperpigmentary disorders are a group of rare genetic pigmentary abnormalities which includes reticulate acropigmentation of Kitamura (RAPK), Dowling-Degos disease (DD), reticulate acropigmentation of Dohi (RAPD), Haber's syndrome, and Galli-Galli disease. A 25-year-old male presented with asymptomatic dark-colored lesions on his hands and feet with light-colored skin lesions involving the trunk since three years. Dermatological examination revealed hyperpigmented macules in a reticulate pattern involving the dorsa of the hands and feet, front and sides of the neck, axillae, periorbital region, and groin. Multiple pits were present over both palms, with breaks in dermatoglyphics. He also had multiple nonacne facial scars predominantly on the nose and malar areas. The patient had overlapping features of RAPK and DDD. In addition, he also had hypopigmented macules and acneiform facial scars. Such an overlap of features of reticulate pigmentation has not been previously reported in the literature.

Whole-exome sequencing identifies ADAM10 mutations as a cause of reticulate acropigmentation of Kitamura, a clinical entity distinct from Dowling-Degos disease

Reticulate acropigmentation of Kitamura (RAK) is a rare genetic disorder of cutaneous pigmentation with an autosomal dominant pattern of inheritance and a high penetration rate. The characteristic skin lesions are reticulate, slightly depressed pigmented macules mainly affecting the dorsa of the hands and feet, which first appear before puberty and subsequently expand to the proximal limb and the trunk. To identify mutations that cause RAK, we performed exome sequencing of four family members in a pedigree with RAK. Fifty-three SNV/Indels were considered as candidate mutations after some condition narrowing. We confirmed the mutation status in each candidate gene of four other members in the same pedigree to find the gene that matched the mutation status and phenotype of each member. A mutation in ADAM10 encoding a zinc metalloprotease, a disintegrin and metalloprotease domain-containing protein 10 (ADAM10), was identified in the RAK family. ADAM10 is known to be involved in the ectodomain shedding of various substrates in the skin. Sanger sequencing of four additional unrelated RAK patients revealed four additional ADAM10 mutations. We identified a total of three truncating mutations, a splice site mutation and a missense mutation in ADAM10. We searched for mutations in the KRT5 gene, a causative gene for the similar pigmentation disorder Dowling-Degos disease (DDD), in all the patients and found no KRT5 mutation. These results reveal that mutations in ADAM10 are a cause of RAK and that RAK is an independent clinical entity distinct from DDD.

Spotted and rippled reticulate hypermelanosis: a possible variant of Dowling?Degos disease

Conflicts of interest: none declared. Sir, Pigmentation disorders derive from melanoblast migration, biogenesis of melanosomes, and secretion of melanosomes into keratinocytes.1 Reticulate hyperpigmentary disorders have been classified into dyschromatosis symmetrica hereditaria (DSH) of Toyama (MIM 127400), dyschromatosis universalis hereditaria (DUH) (MIM 127500), Dowling–Degos disease (DDD) (MIM 179850) and reticulate acropigmentation of Kitamura (RAK). We encountered a 3‐year‐old girl showing asymptomatic and asymmetrical, spotted and rippled reticulate hypermelanosis without hypomelanosis. Here, we discuss the similarities to and differences from previously defined disorders. A 3‐year‐old Japanese girl presented with spotted and rippled reticulate hypermelanosis without hypopigmented spots. The pigmentation showed an asymmetrical distribution. The pigmentation gradually developed from the age of 1 year. Rippled reticulate hypermelanosis was observed around the left axilla, and faint hypermelanosis around the right axilla. Spotted and rippled reticulate hypermelanosis was present on the flexures of the extremities, especially on the right thigh (Fig. 1a). Spotted reticulate hypermelanosis was present on the dorsa of the hands and feet (Fig. 1b). The dorsum of the left foot showed more pronounced hypermelanosis (Fig. 1b). V‐neck‐shaped asymmetrical hyperpigmentation was observed. The patient had normal palms and soles, and no other cutaneous abnormalities. Her relatives did not have reticulate hyperpigmentation. Skin biopsies were taken from sun‐protected areas of the upper back: a hyperpigmented lesion on the left side and a normal skin‐coloured lesion on the right side. Histopathology of both biopsy specimens showed the same features. Haematoxylin and eosin staining showed no papillary downgrowth of the epidermis. Fontana–Masson staining indicated asymmetrical distribution of melanin granules and persistence of melanin granules through the epidermis (Fig. 2a). Electron microscopy showed a small number of stage II melanosomes, about 45% of melanosomes being stage III, and the remainder stage IV (Fig. 2b).

Reticulate Acropigmentation of Kitamura: First Case Reports from Nepal

Two young Nepalese females, aged 34 and 17 years, presented with multiple small brown macules in a reticulate pattern on the distal extensor aspects of their limbs. The first patient's daughter also had similar lesions. The second patient had similar lesions on her eyelids and palmar pits as well. The clinical diagnosis of reticulate acropigmentation of Kitamura (RAK) was made in both the patients and was confirmed histopathologically. These are the first case reports of this condition from Nepal.

Is the Heredity of Reticulate Acro Pigmentation of Kitamura always Autosomal Dominant?

Reticulate acropigmentation of Kitamura (RAK) in three patients and their families is described. In one family, 2 women and 2 men were affected out of 9 individuals. In the other family, 6 women had lesions of reticulate acropigmentation out of total of 27 over three generations. In the third family, one man was affected. All of the cases had palmar pits; onset of lesions was after puberty in all the cases. The apparently different hereditary patterns in these three families are striking, and autosomal dominant inheritance appears unlikely in every case.

Familial reticulate acropigmentation of Dohi

Reticulate acropigmentation (RA) comprises dyschromic disorders that generally have an autosomal dominant pattern of inheritance, Two main forms of RA have been described: reticulate acropigmentation of Kitamura (RAK) and reticulate acropigmentation of Dohi (RAD). We observed a 21-year-old white woman who had progressive reticulate hyper- and hypopigmentation on the volar surface of her forearms and the dorsa of her hands. Many of her relatives have similar lesions. There were no pits or breaks in the epidermal ridge pattern on the palms. A biopsy specimen revealed areas with an excess of melanin in the basal layer alternating with others in which melanin was totally absent, Electron microscopic findings in a hypermelanotic area showed an increased number of melanocytes with high metabolic activity. In the hypomelanotic areas the melanocytes were morphologically abnormal with melanosomes at the early stages of development. (J Am Acad Dermatol 1997;37:884-6.)

Spectrum of reticulate flexural and acral pigmentary disorders in northern India.

Reticulate pigmentary disorders are rare in India. Only 15 cases of reticulate acropigmentation of Kitamura (RAPK) and 9 cases of Dowling-Degos disease (DDD) have been reported previously. To the best of our knowledge, there has been no earlier report of acropigmentation of Dohi. We herein describe 10 patients with various reticulate pigmentary abnormalities: 6 with RAPK, 2 with DDD, 1 with RAPK-DDD overlap, and 1 with acropigmentation of Dohi. Palmar pits and/or breaks in epidermal ridge pattern were absent in 2 of 6 patients with RAPK. A 23-year-old male patient had RAPK-DDD overlap. Periorbital pigmentation and pigmentation over the mucosal surface of the prepuce and corona of the glans penis were some unique features observed in this patient. His sister and mother had RAPK and DDD, respectively. We concluded that RAPK and DDD are varying manifestations of a single entity. Their presence in other family members probably depends on the degree of penetrance.

RETICULATE ACROPIGMENTATION OF KITAMURA: TWO CASE REPORTS

Reticulate acropigmentation of Kitamura (RAK) is an autosomal dominantly inherited dermatosis. Two patients are described with the clinical and histopathologic features of reticulate acropigementation of Kitamura. We speculate that RAK and the Dowling-Degos disease (DDD) are the same diseases.

Behavior of Melanocytes in Reticulate Acropigmentation of Kitamura

Four patients with reticulate acropigmentation of Kitamura (RAPK) had reticulate pigmentation that was slightly depressed below the skin surface. Histologic findings revealed epidermal atrophy, elongation of the rete ridges with large amounts of melanin, and an increased number of dopa-positive basal melanocytes. Electron microscopic findings showed many melanosome complexes within the keratinocytes, dendrites filled with numerous melanosomes, and some melanosome complexes within the melanocytes. It is concluded that the hyperpigmentation of RAPK is due to increased number of active melanocytes and to increased transfer of melanosomes to surrounding keratinocytes.

Reticulate Acropigmentation of Kitamura

In 1943, Kitamura and Akamatsu¹described a male patient who had a reticulate pattern of freckle-like, slightly depressed macules on the extensor surfaces of his hands and feet. Two similar patients were described in 1953 by Kitamura et al.²Seven further cases that were reported by Griffiths³in 1976 were the first to be described outside of Japan. Griffiths' cases came from Asia, Africa, and Europe. We believe that this may be the first case of reticulate acropigmentation of Kitamura (RAPK) to be described in the Americas. <h3>Report of a Case</h3> A 17-year-old girl was seen in a dermatology clinic with small, 1- to 4-mm, depressed, pitted macules, in a reticulate pattern, on the palmar and dorsal aspects of her hands and on the plantar and dorsal aspects of her feet (Figure). The lesions were first noted when the patient was 3 years old, and they progressively