|LETTER TO EDITOR
|Year : 2015 | Volume
| Issue : 1 | Page : 64-66
Hypomelanosis of Ito with seizures in a mentally retarded child
Anupam Das1, Dibbendhu Khanra2, Indrashis Podder1, Nilay Kanti Das1
1 Department of Dermatology, Medical College and Hospital, Kolkata, West Bengal, India
2 Department of General Medicine, Medical College and Hospital, Kolkata, West Bengal, India
|Date of Web Publication||26-Jun-2015|
Department of Dermatology, Medical College and Hospital, Kolkata, West Bengal
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Das A, Khanra D, Podder I, Das NK. Hypomelanosis of Ito with seizures in a mentally retarded child. Pigment Int 2015;2:64-6
A 16-year-old, mentally retarded male patient with delayed development of motor and speech milestones and intractable seizures, was referred to our Dermatology Department, after consulting other physicians. There was no consanguinity in the parents, and two of his younger brothers were normal. The patient started to have multiple episodes of seizures since the age of 11 years, and he was put on phenytoin, clobazam, and levetiracetam for the management of epilepsy. The mother complained of multiple white-colored patches over the upper limb and trunk of her son, which were present since birth. There was no history of any preceding vesiculobullous lesion. On examination, multiple congenital nonitchy, hypopigmented patches were found over the trunk and left upper limb. Besides, he had narrow semicircular streaks of hypopigmentation on the left side of trunk sweeping over to flank and back in an S-shaped pattern [Figure 1]a and b and a linear distribution over the extensor surface of left upper limb [Figure 2]a and b; conspicuously showing a Blaschkoid distribution, without involving face, palms, and soles. The patches were nontender and sensations were intact. In addition to this, there were multiple acneiform eruptions on the face [Figure 3]. The ophthalmic examination was noteworthy for strabismus. Examination of the oral cavity showed defective implantation of teeth, gingival hyperplasia, and increased space between the teeth. The patient's parents refused skin-biopsy. The baseline blood investigations, thyroid function tests, and skeletal survey were within normal limits. Magnetic resonance imaging (MRI) of the brain showed diffuse brain atrophy [Figure 4]. Electroencephalography showed spike and wave discharges bilaterally. Based on the characteristic clinical findings, and the consistent MRI; we arrived at the diagnosis of hypomelanosis of Ito (HI) or incontinentia pigmenti achromians.
|Figure 1: (a and b) Hypopigmented streaks on left side of trunk sweeping over to flank and back in an S-shaped pattern|
Click here to view
|Figure 2: (a and b) Linear distribution of hypopigmentation over the extensor surface of left upper limb|
Click here to view
|Figure 3: Strabismus, gingival hyperplasia, and acneiform eruptions on the face|
Click here to view
|Figure 4: Magnetic resonance imaging of the brain showed diffuse brain atrophy|
Click here to view
Hypomelanosis of Ito, a sporadic neurocutaneous disorder is characterized by asymmetric whorl-like or linear hypopigmented macules, presenting unilaterally or bilaterally along the Lines of Blaschko More Details. First recognized by a Japanese dermatologist, Minor Ito in 1952, clinically, the lesions appeared as a negative image of incontinentia pigmenti and were thus christened as incontinentia pigmenti achromians.  Although first reported in Japanese patients, it has been observed in many other ethnicities as well. This entity may be discernible at birth, if not; it is recognizable during the neonatal period or early childhood.
The cutaneous lesions may involve any part of the body. Abnormalities of sweat glands and nails have also been reported. Associations include café-au-lait spots, nevus marmorata, angiomatous nevi, nevus of Ota, and slate gray spots.  Extracutaneous congenital abnormalities are found in a staggering 50% of cases, central nervous system being involved most commonly usually manifesting as mental retardation, seizure disorders, and speech delay. Other abnormalities include scalp and hair changes, dental, ocular, musculoskeletal defects, cardiac and urogenital malformations. In view of the common occurrence of extracutaneous abnormalities, several workers have described HI as nonspecific manifestation (phenotype) of chromosomal mosaicism; rather than a single disease entity. 
Chromosomal mosaicism is believed to account for the phenotypic variations. Several chromosomal anomalies like those on 9q33, 15q11-q13, Xp11, and Xp21.2 have been implicated, among which the genomic mosaicism of 9q33 is the most characteristic.  Genetic analysis could not be done in our case due to lack of facilities.
A Fontana-Masson stain of a hypopigmented lesion shows reduced melanin granules in the basal layer and a complete absence of melanin in some areas. Fewer and smaller melanocytes with sparse, short dendrites are the findings in a 3,4-dihydroxyphenylalanine reaction. Electron microscopic findings include decreased number of melanosomes in melanocytes and keratinocytes.  The skin lesions have to be distinguished from the more bizarre-shaped depigmented naevi and from focal dermal hypoplasia where the skin shows atrophic changes as well.  Unfortunately, our patient's parents refused skin biopsy. Other differentials which need to be considered are tabulated below [Table 1].
The usual finding on MRI is cortical atrophy (as in our case), periventricular white matter changes, hypoplastic corpus callosum, vascular changes etc.; however, occasionally, some novel findings may be obtained like ipsilateral pachygyria and absence of the anterior limb of the sylvian fissure.  Since neurologic manifestations such as cognitive delay and epileptic seizures are the most common cerebral manifestations, the entity HI has now been classified under neurocutaneous syndromes. Recently, Pavone et al. studied a series of cases of HI along with the characteristic features of the epileptic episodes. 
In our case, a neurocutaneous disorder with ocular and dental changes was classical of HI. Gum hypertrophy and acneiform eruptions were attributable to prolonged phenytoin therapy (for seizures). There is no effective therapy for the cutaneous lesions. Multidisciplinary care with periodic consultations with an ophthalmologist, neurologist, and orthopedic specialist is quintessential. Seizures should be treated with multiple anticonvulsants. This case has been reported to stress on the importance of dermatological examination to arrive at the correct diagnosis.
| References|| |
Ito M. Studies on melanin XI: Incontinentia pigmenti achromians. A singular case of nevus depigmentosus systematicus bilateralis. Tohoku J Exp Med 1952;55:57-9.
Griebel V, Krägeloh-Mann I, Michaelis R. Hypomelanosis of Ito - Report of four cases and survey of the literature. Neuropediatrics 1989;20:234-7.
Ruggieri M, Pavone L. Hypomelanosis of Ito: Clinical syndrome or just phenotype? J Child Neurol 2000;15:635-44.
Irvine AD, Mellerio JE. Hypomelanosis of Ito. In: Burns T, Breathnach S, Cox N, Griffiths C, editors. Rook's Textbook of Dermatology. 8 th
ed. West Sussex: Wiley Blackwell Publishers; 2010. p. 58.45.
Cavallari V, Ussia AF, Siragusa M, Schepis C. Hypomelanosis of Ito: Electron microscopical observations on two new cases. J Dermatol Sci 1996;13:87-92.
Muhammed K, Mathew J. Coexistence of two neurocutaneous syndromes: Tuberous sclerosis and hypomelanosis of Ito. Indian J Dermatol Venereol Leprol 2007;73:43-5.
Shobha N, Taly AB, Sinha S, Arunodaya GR, Srikanth SG. Neurological pictures. Hypomelanosis of Ito. J Neurol Neurosurg Psychiatry 2006;77:873.
Pavone P, Praticò AD, Ruggieri M, Falsaperla R. Hypomelanosis of Ito: A round on the frequency and type of epileptic complications. Neurol Sci 2015; [Epub ahead of print].
[Figure 1], [Figure 2], [Figure 3], [Figure 4]