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 Table of Contents  
Year : 2017  |  Volume : 4  |  Issue : 2  |  Page : 109-111

Unilateral reticulate pigmentation of Kitamura

Postgraduate Department of Dermatology, STD & Leprosy, Government Medical College, University of Kashmir, Srinagar, Jammu and Kashmir, India

Date of Web Publication1-Dec-2017

Correspondence Address:
Gousia Sheikh
Postgraduate Department of Dermatology, STD & Leprosy, Government Medical College, University of Kashmir, Srinagar - 190 010, Jammu and Kashmir
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/2349-5847.219685

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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.

Keywords: Acropigmentation, genodermatosis, reticulate pigmentation, unilateral

How to cite this article:
Sheikh G, Bhat YJ, Mir MA, Hassan I. Unilateral reticulate pigmentation of Kitamura. Pigment Int 2017;4:109-11

How to cite this URL:
Sheikh G, Bhat YJ, Mir MA, Hassan I. Unilateral reticulate pigmentation of Kitamura. Pigment Int [serial online] 2017 [cited 2023 Mar 26];4:109-11. Available from: https://www.pigmentinternational.com/text.asp?2017/4/2/109/219685

  Introduction Top

Reticulate pigmentary disorders are rare genetic abnormalities generally inherited in an autosomal dominant manner. These disorders include reticulate acropigmentation of Kitamura (RAPK), Dowling–Degos disease (DDD), reticulate acropigmentation of Dohi (RAPD), Haber’s syndrome, and Galli–Galli disease.[1]

RAPK is clinically characterized by reticulate, slightly depressed pigmented macules on the acral parts of body (mainly the dorsa of the hands and feet). The lesions start in the first and second decades of life and gradually extend onto the extremities and rarely on the face and eyelids. The lesions usually darken slowly over time.[2] Pits and breaks in the dermatoglyphics are found on the palms, soles, and dorsal phalangeal surfaces.[3]

  Case report Top

A 29-year-old female presented with asymptomatic, dark colored skin lesions on the left side of her body, including the face, neck, trunk, left upper and lower limb, and dorsum of left hand and foot since 8 years. There was no history of consanguinity. The lesions had first appeared on the dorsum of left hand and, over a period of 2 to 3 years, progressed to involve most of the left side of her body. There was no history of photosensitivity or prolonged intake of any drugs.

Dermatological examination revealed hyperpigmented, atrophic, angulated macules in a reticulate pattern involving only the left side of her body with a clear midline demarcation [[Figure 1],[Figure 2],[Figure 3]]. There was a relative sparing of flexures. Multiple pits with breaks in dermatoglyphics were present over the left palm only [Figure 4]. Mucous membranes and scalp were not involved. Hair was black in color, and nails and teeth were normal. Skin biopsy of a hyperpigmented macule over the trunk revealed elongation of rete ridges with increased number of melanocytes in basal layer of epidermis. Occasional melanophages were seen in dermis [Figure 5]. A diagnosis of unilateral reticulate pigmentation of Kitamura was made.
Figure 1: Clear midline demarcation of the reticulate pigmented macules

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Figure 2: Patchy reticulate pigmentation on the back

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Figure 3: Patchy reticulate angulated pigmented macules on left foot only

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Figure 4: Multiple pits on left palm with breaks in dermatoglyphics with sparing of right palm

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Figure 5: Increased number of melanocytes in basal layer with occasional melanophages in dermis (H&E 400X)

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  Discussion Top

RAPK was first described by Kitamura and Akamatsu[4] in Japan. So far, near about 100 cases have been reported, mostly in dark skinned individuals of Asian ethnic origin.[5] Clinically, RAPK is characterized by pigmented, angulated, slightly atrophic, and hyperpigmented macules over the distal extremities.[2] On histopathological examination, epidermis shows atrophy with club-like elongation of the rete ridges and an excess of melanin in the basal layer.[5]

The differential diagnosis of RAPK includes dyskeratosis congenita, dyschromatosis universalis hereditaria, Franceschetti–Jadassohn’s syndrome, dermatopathia pigmentosa reticularis, RAPD, and DDD [Table 1]. The differentiation between RAPD and RAPK is based on clinical and histological findings. In RAPK, there are usually no hypopigmented macules with histology showing epidermal atrophy and increase in the number of basal melanocytes. In DDD, reticular hyperpigmentation on flexor areas is seen and on histology pigmented filiform epidermal projections, involving the follicular infundibulum as well as the epidermis are seen. Comedo-like lesions and pitted perioral acneiform scars may also be present.[6]
Table 1: Differential diagnosis of reticulate acropigmentation of Kitamura

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Many authors have proposed that DDD and RAPK may be an extended spectrum of a single entity, as numerous cases with overlapping features have been reported.[7],[8] However, molecular studies show mutations of KRT5 and POGLUT1, specifically in patients of DDD,[9] whereas patients of RAPK are shown to have mutations in ADAM10.[10] Still a group of patients with overlapping features of DDD and RAPK had mutations in POFUT1 gene.[11]

Our patient had skin lesions which are characteristically seen in RAPK and the cutaneous biopsy also favored the diagnosis of RAPK. However, the involvement was both acral as well as nonacral. Specifically, our patient had a unilateral distribution of the lesions which is unheard of in RAPK. So our patient was a case with unilateral nonacral reticulate pigmentation of Kitamura. No significant treatment is available. Most treatments attempted for this disorder have been unsuccessful. However, treatment with 20% azelaic acid has shown significant improvement in some cases.[3]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Mohana D, Verma U, Amar AJ, Choudhary R. Reticulate acropigmentation of Dohi: A case report with insight into genodermatoses with mottled pigmentation. Indian J Dermatol 2012;57:42-4.  Back to cited text no. 1
[PUBMED]  [Full text]  
Sharma R, Sharma SC, Radotra BD, Kaur S. Reticulate acropigmentation of Kitamura. Clin Exp Dermatol 1989;14:302-3.  Back to cited text no. 2
Kameyama K, Morita M, Sugaya K, Nishiyama S, Hearing VJ. Treatment of reticulate acropigmentation of Kitamura with azelaic acid. An immunohistochemical and electron microscopic study. J Am Acad Dermatol 1992;26:817-20.  Back to cited text no. 3
Griffiths GA. Reticulate acropigmentation of Kitamura. Br J Dermatol 1976;95:437-43.  Back to cited text no. 4
Chang MW. Disorders of hyperpigmentation. In: Bolognia JL, Jorizzo LJ, Rapini RP, editors. Dermatology. 2nd ed. USA: Elsevier; 2007. p. 939–63.  Back to cited text no. 5
Alfadley A, Al Ajlan A, Hainau B, Pedersen KT, Al Hoqail I. Reticulate acropigmentation of Dohi: A case report of autosomal recessive inheritance. J Am Acad Dermatol 2000;43:113-7.  Back to cited text no. 6
Cox NH, Long E. Dowling-Degos disease and Kitamura’s reticulate acropigmentation: Support for the concept of a single disease. Br J Dermatol 1991;125:169-71.  Back to cited text no. 7
Rathoriya SG, Soni SS, Asati D. Dowling-Degos disease with reticulate acropigmentation of Kitamura: Extended spectrum of a single entity. Indian Dermatol Online J 2016;7:32-5.  Back to cited text no. 8
[PUBMED]  [Full text]  
Basmanav FB, Oprisoreanu AM, Pasternack SM, Thiele H, Fritz G, Wenzel J et al. Mutations in POGLUT1, encoding protein O-glucosyltransferase 1, cause autosomal-dominant Dowling-Degos disease. Am J Hum Genet 2014;94:135-43.  Back to cited text no. 9
Kono M, Sugiura K, Suganuma M, Hayashi M, Takama H, Suzuki T et al. Whole-exome sequencing identifies ADAM10 mutations as a cause of reticulate acropigmentation of Kitamura, a clinical entity distinct from Dowling-Degos disease. Hum Mol Genet 2013;22:3524-33.  Back to cited text no. 10
Basmanav FB, Fritz G, Lestringant GG, Pachat D, Hoffjan S, Fischer J et al. Pathogenicity of POFUT1 in Dowling–Degos disease: Additional mutations and clinical overlap with reticulate acropigmentation of Kitamura. J Invest Dermatol 2015;135:615.  Back to cited text no. 11


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]

  [Table 1]


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