Naevoid Blaschkoid psoriasis

Ashok Krishnarao Ghorpade

 Department of Dermatology, Venereology & Leprosy, J. L. N. Hospital & Research Centre, Bhilai Steel Plant, Bhilai, India

Correspondence Address:
Ashok Krishnarao Ghorpade
BK D-18, Sector 9, Bhilai (Chhattisgarh) - 490 009
India

Sir,

A three-year-old male child was brought for asymptomatic skin lesions on buttock and thigh since birth. The lesions had started on his left buttock and gradually increased linearly over to the left thigh. There was no history of seasonal variation, systemic complaints, topical or oral medication or family history of any skin lesions. Cutaneous examination showed numerous whitish scaly, confluent and discrete papular lesions and plaques arranged in linear bands along the lines of Blaschko extending from the left buttock onto the postero-lateral aspects of left thigh up to the knee joint [Figure - 1]. Koebner′s phenomenon was observed over the buttock and thigh. The bands were of about 16 cm in length and 6 cm in width. Auspitz sign was positive. There were no scaly skin lesions elsewhere. The scalp and nails were normal. Skin biopsy from the scaly plaque revealed hyperkeratosis, parakeratosis, thinned granular layer, Munro′s microabscesses, irregular acanthosis and papillomatosis with dilated capillaries in the tips of papillae [Figure - 2]. A diagnosis of naevoid Blaschkoid psoriasis was made. The patient was treated with topical 1% hydrocortisone acetate cream, to which he showed little response after six weeks use. The patient was subsequently lost to follow-up.

Though psoriasis may be observed in childhood, congenital psoriasis starting at birth is rare. ^{[1],[2],[3],[4]} A few of those observed, developed classical psoriasis later in life. ^[3,4] Atherton et al.,[3] reported multiple psoriasiform plaques, arranged linearly along the lines of Blaschko. Al Fouzon et al., ^[4] observed a 10-year-old girl with two localized psoriasiform plaques at birth, subsequently developing generalized scaly plaques along the lines of Blaschko. The histopathology, the disease course and HLA association, suggested psoriasis. Naevoid psoriasis probably reflects mosaicism for a gene responsible for psoriasis. ^{[1],[2],[3],[5],[6]} Some consider that these represent the inflammatory linear verrucous epidermal naevus (ILVEN), ^[3] but absence of itching, distribution of lesions, the histopathology and therapeutic response to ultraviolet radiation are against it. ^[4],[6] The naevoid psoriasis might co-exist with or develop as an isomorphic phenomenon over a pre-existing ILVEN. ^[5]

The lines of Blaschko in contrast to dermatomes, form a V-shape over the spine and S-shape on the lateral and anterior aspect of trunk, run perpendicularly on limbs and form whorls over the abdomen. They represent a form of ′Mosaicism′, are distinct from other known linear patterns of the skin, do not relate to any vascular or lymphatic structures and represent developmental growth pattern of the skin. ^[4],[5] Many nevoid and acquired skin conditions may follow these lines including incontinentia pigmenti, focal dermal hypoplasia, epidermal nevus, sebaceous nevus, lichen nitidus, lichen planus, lichen striatus, lupus erythematosus, vitiligo and psoriasis. ^{[1],[2],[3],[4],[5],[6],[7]}

According to Lehman and Rahil, ^[7] though childhood psoriasis is common, congenital psoriasis (psoriasis present at birth) appears to be quite rare . In their review, they could find only nine documented cases of congenital psoriasis till 2008. In their analysis of congenital psoriasis, involvement was commonly seen on face, scalp, chest and trunk, while the buttocks were usually spared. ^[7] There was no family history of psoriasis, and the lesions persisted despite therapy. The authors felt that additional reports with extended follow-up were needed to better characterize this condition. ^[7] In a study of 419 cases of childhood psoriasis from north India, infantile psoriasis (below 1 year of age) accounted for 3.5% of patients, the youngest being a four day old child, but none had lesions at birth. ^[8]

A case of "Accentuated Blaschko-linear psoriasis", with co-existing scaly plaques elsewhere, was recently reported by the author. ^[2] The diagnosis in the present case was suggested by the history and the clinical features and confirmed histopathologically. The involvement of buttock in this and one previous report ^[2] by the author seem to be unusual, as they were found to be usually spared in the analysis of previously reported cases. ^[7] Like most of the earlier reports, here also there was not much response to topical therapy. The present and the earlier reports of congenital psoriasis suggest that psoriasis can manifest at birth, and that naevoid psoriasis should get the recognition as a separate entity. ^{[1],[2],[3],[4]}

1.	Ghorpade A. Linear naevoid psoriasis along lines of Blaschko. J Eur Acad Dermatol Venereol 2004;18:726-7. [Google Scholar]
2.	Ghorpade A. Accentuated Blaschko-linear manifestation of psoriasis. Eur J Dermatol 2008;18;196-7. [Google Scholar]
3.	Atherton DJ, Kahana M, Russell-Jones R. Naevoid psoriasis. Br J Dermatol 1989;120:837-41. [Google Scholar]
4.	al-Fouzan AS, Hassab-el-Naby HM, Nanda A. Congenital linear psoriasis: A case report. Pediatr Dermatol 2008;7:303-6. [Google Scholar]
5.	Goujon C, Pierini AM, Thivolet J. Does linear psoriasis exist? Ann Dermatol Venereol 1981;108:643-50. [Google Scholar]
6.	Lehners-Weber C, de la Brassinne M, Dezfoulian B, Richert B, Bonardeaux C, Willemaers V. Congenital psoriasis following the lines of Blaschko. Pediatr Dermatol 1996;13:219-21. [Google Scholar]
7.	Lehman JS, Rahil AK. Congenital psoriasis: Case report and literature review. Pediatr Dermatol 2008;25:332-8. [Google Scholar]
8.	Kumar B, Jain R, Sandhu K, Kaur I, Handa S. Epidemiology of childhood psoriasis: A study of 419 patients from northern India. Int J Dermatol 2004;43:654-8. [Google Scholar]