|Year : 1992 | Volume
| Issue : 1 | Page : 30-32
Hypomelanosis of ITO
Sanjay Singh, Vineet Kaur, SS Pandey
Source of Support: None, Conflict of Interest: None
Three Indian children developed lesions of hypomelanosis of ITO since the age of 1 year, 9 months and 5 years respectively. Cases 1 and 3 had borderline intellectual functioning and case 1 showed diminished sweat response. There were no other associated abnormalities. Several recent reports have suggested that hypomelanosis of Ito is a nonspecific marker of chromosomal mosaicism.
Keywords: Hypomelanosis of Ito
|How to cite this article:|
Singh S, Kaur V, Pandey S S. Hypomelanosis of ITO. Indian J Dermatol Venereol Leprol 1992;58:30-2
| Introduction|| |
Minor Ito described a condition which he named incontinentia pigmenti achromians (IPA) because of the resemblance of its pattern of hypopigmentation to the hyperpigmentation of incontinentia pigmenti of Bloch - Siemens - Sulzberger (IP). The confusion regarding the relationship between IPA and IP  has been cleared in favour of these being distinct entities.  Jelinec et first proposed that IPA called hypomelanosis of Ito (HI), a suggestion now widely accepted. We report 3 Indian patients of HI.
| Case Reports|| |
Case 1 : A 2 1/ 2 - year-old boy presented with asymptomatic, non scaly, sharply demarcated hypopigmented macules arranged in 2 semicircular bands on right side of abdomen. Beginning at the same point on the right lateral side, the bands had gradually moved away from each other, their lower ends being placed wide apart. The upper band, which was broader and longer than the lower band, first made a semicircle and then ran obliquely across the right half of abdomen to end at the umbilicus [Figure - 1]. The macules, first appearing at 1 year of age, had enlarged and became prominent over the time and their present arrangement became obvious in about 6 months.
Case 2 : This 1 - year-old fair girl had developed non itchy, non scaly, hypopigmented macules on the trunk and upper limbs for past 3 months. The lesions were prominently seen under Wood's light. The macules were arranged in bands, which ran across the trunk, vaguely encircling it in the form of ripples [Figure - 2]. On the upper limbs, the bands were placed more or less along the length of the limbs. As the baby was growing, the lesions were increasing in size.
Case 3: This girl of 7 years had asymptomatic, non scaly, hypopigmented macules arranged in band-like and guttate patterns on both sides of chest and all around right arm. The bands had whorled configuration at places on the chest, while on the right arm they were more or less . parallel. The lesions, which appeared 2 years back, were progressively increasing in size and degree of hypopigmentation.
In all 3 cases, the lesions were not preceded by inflammation. Patients had no other complaints; their growth rate, increase in body weight, hair, teeth, nail and funduscopic examination were normal. They were alert and had no abnormalities of the eyes, central nervous system (CNS) or musculoskeletal system. Case 1 and 3 had borderline intellectual functioning (IQ 76 and 80 as revealed by Stanford-Binet test and Wechsler intelligence scale for children revised, respectively). IQ of case 2 was not tested. Case 1 and 3 were the only children of their parents, while case 2 had one elder brother. There was no consanguinity in the parents and nobody in the families had similar lesions.
Sweating test was done in all 3 cases. Parts of the lesions were painted with 2% iodine in alcohol and were allowed to dry. Then, starch suspended in castor oil (50 g in 100ml.) was painted onto the iodine treated skin. Numerous dark spots appeared at the test sites in cases 2 and 3 after 15 to 30 minutes, but no change was seen in case 1 even after 1 hour.
A biopsy was taken from the hypopigmented macule in case 1, H & E preparation showed decreased content of pigment granules in the basal cells of the epidermis. No other abnormality was seen histologically and dopa reaction was not studied.
| Comments|| |
Patients of HI have areas of hypopigmentation distributed over the body according to the Lines of Blaschko More Details.  The first patient described by Ito did not appear to have any other abnormality except hypopigmentation. After that several associated abnormalities have been described.  These include; cns : motor retardation, mental retardation, seizures, eeg abnormalities; ocular : strabismus, epicanthic folds, myopia; musculoskeletal hypertelorism, malformed auricle, arm leg length discrepancy; hair: diffuse alopecia, generalized hirsuitism, facial hypertrichosis; skin : decreased sweat response, decreased capillary resistance, IP, morphoea, ichthyosis; nails : transverse ridging; and dental : anodontia, dysplasia. Our patients 1 and 3 had borderline intellectual functioning and patient 1 showed decreased sweat response.
Though most of the cases have been reported from Japan, HI has been reported from several other countries.  Most reported patients are less than 10 years old and sex ratio favoured females by 2.5 : 1. 
Lately there has been renewed interest in HI with the reports that many patients of HI have associated chromosomal mosaicism. An association between the pigmentary anomaly and chromosomal mosaicism, which is specific neither for a particular type of chromosomal aberration nor for HI, has been suggested.  This association lends support to the hypothesis that the pattern of hypopigmentation in HI is the result of the migration of two clones of primordial melanocytes, each with a different pigment potential.  A pattern reminiscent of Blaschko lines is formed when these 2 cell lines alternate in their arrangement along the length of the embryo, while different patterns will appear when this alternating arrangement of neural crest cells is not established.
| References|| |
|1.||Takematsu H, Sato S, Igarashi M, et al. Incontinentia pigmenti achromians (Ito). Arch Dermatol 1983; 119: 391-5. [PUBMED] |
|2.||Mosher D B, Fitzpatrick T B, Ortonne J P, et al. Disorders of pigmentation. In : Dermatology in General Medicine (Fitzpatrick T B, Eisen A Z, Wolff K, et al ads), 3rd edn. New York : Mc Graw Hill Book Company, 1987 ; 794-875. |
|3.||Jelineck JE„ Bart RS, Schiff GM. Hypomelanosis of Ito, incontinentia pigmenti achromians. Report of three cases and review of the literature. Arch Dermatol 1973; 107 596-601. |
|4.||Jackson R. The lines of Blaschko : a review and reconsideration. Br J Dermatol 1976; 95: 349 - 59. [PUBMED] |
|5.||Thomas I T, Frias J L. (Letter to the editor) Lancet, 1986; 2: 343. |
[Figure - 1], [Figure - 2]