|Year : 2015 | Volume
| Issue : 3 | Page : 139-141
Samujjala Deb1, Sandipan Dhar2
1 Department of Dermatology, Burdwan Medical College and Hospital, Burdwan, India
2 Department of Pediatric Dermatology, Institute of Child Health, Kolkata, West Bengal, India
|Date of Web Publication||10-Jul-2015|
C-4, New Raipur, Ganguly Bagan, Kolkata - 700 084, West Bengal
Source of Support: Nil, Conflict of Interest: None declared.
Pigmented xerodermoid is a variant of xeroderma pigmentosum (XP-V). It occurs at a later age with the onset in the third or fourth decade of life in comparison to XP which mostly becomes manifest within 1–2 years after birth. It is more common in regions where consanguinity and marriages between close relatives are practiced and also in the tropics where there is greater exposure to sunlight and ultraviolet radiation. XP has seven complementation groups namely A-G and an XP-V. Recently, the XP-V is considered to be the same as pigmented xerodermoid.
Keywords: Genodermatoses, photosensitivity, pigmented xerodermoid
|How to cite this article:|
Deb S, Dhar S. Pigmented xerodermoid. Indian J Paediatr Dermatol 2015;16:139-41
| Introduction|| |
Xeroderma pigmentosum (XP) is inherited as an autosomal recessive disease with a frequency of 1 in 1 million persons in Europe and the United States.
The complementation groups have been found to be associated with biallelic mutations in nucleotide excision repair genes: XPA, ERCC1, ERCC3 (XP-B), XPC, ERCC2 (XP-D), DDB2 (XP-E), ERCC4 (XP-F), and ERCC5 (XP-G) and also with mutations in the DNA bypass polymerase POLH. The variant XP (XP-V) has normal nucleotide excision repair of UV-damaged DNA, but they have a defect in the error-prone polymerase, DNA polymerase eta (encoded by POLH). Thus, there is complete depression of DNA synthesis on exposure to ultraviolet radiation.
Xeroderma pigmentosum is clinically characterized by photosensitivity, freckle-like pigmentation, hypo- and hyper-pigmentation, ocular changes like photophobia, keratitis etc., and early onset of malignant cutaneous neoplasms. A proportion of patients also have neurologic abnormalities.
Pigmented xerodermoid or XP-V patients have cutaneous and ocular manifestations similar to XP, but neurologic involvement is rare. Clinical features may be mild in some and severe in others.
| Case report|| |
A young 5-year-old boy born of a nonconsanguineous marriage was brought to the outpatient department with complaints of progressively increasing pigmentation freckles and pigmentation involving the face and dorsa of hands and feet. The child also gave a history of burning sensation when playing outside in the sun. There was no history of similar lesions in any of the other family members. On examination, there was freckle like pigmentation over the face, ears, neck, upper back, arms, legs, and dorsa of hands and feet [Figure 1][Figure 2][Figure 3]. The pigmentation was more prominent in the sun-exposed parts of the body. The nature of the pigmentation was in the form of multiple small (2–3 mm) hyper-pigmented macules interspersed with hypo-pigmented ones. The skin was dry and lusterless. There was mild redness of the conjunctiva of both the eyes. Rest of the systemic examination was within normal limits, and the boy was in good health overall.
|Figure 3: Similar freckle-like pigmentation over the extensor aspect of arms|
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On the basis of typical clinical finding and distribution, the child was diagnosed as having pigmented xerodermoid. The parents were counseled about the nature of the disease and were advised to undergo genetic counseling and testing in case they planned for another child in the future. The boy was prescribed a topical sunscreen and advised to avoid excess sun exposure. The parents were also advised to bring the boy for regular follow-up and to observe the appearance of any suspicious lesion over the skin.
| Discussion|| |
Pigmented xerodermoid is a rare genodermatoses with few reports in the literature. In the early seventies, when it was first reported, it was often referred to as the “XP of late onset.”, Only a few cases have been previously reported from India by Das et al. and Bhat et al., Classic XP has an onset with the first 1 year of life. The skin becomes dry parchment-like with multiple hyper-pigmented freckles. There is a 1000 fold higher chance of developing basal cell carcinoma, squamous cell carcinoma, and malignant melanoma. Pigmented xerodermoid has a later age of onset, but the risk of developing malignancies definitely there and needs to be kept in mind.
Clinically, pigmented xerodermoid needs to be differentiated from other XP-V, XP with neurologic abnormalities, Cockayne syndrome (CS), the XP/CS complex, trichothiodystrophy (TTD), the XP/TTD complex, cerebrooculofacioskeletal (COFS) syndrome, COFS/TTD, CS/TTD complex, and the UV-sensitive syndrome and other diseases with cutaneous photosensitivity like Rothmund–Thomson syndrome, Hartnup disease among a few.
Treatment consists of stringent photoprotection of the skin and eyes. Cigarette smoke should be avoided (since it contains carcinogens like the benzopyrene) and lubricating eye drops must be used. Total body examinations must be carried out at regular intervals for early identification of malignancies. Premalignant lesions like actinic keratoses may be treated with cryotherapy and malignancies treated along same protocols as in patients without XP. Isotretinoin and acitretin may be tried to prevent cutaneous malignancies. Since the exposure to sunlight is minimized, Vitamin D may be given prophylactically to prevent bone fractures.
Affected parents can undergo genetic testing to find out the risk of having an offspring with the disease. Prenatal testing and genetic counseling have an important role to play in the diagnosis and management of the disease.
| References|| |
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[Figure 1], [Figure 2], [Figure 3]