A case of ichthyosis hystrix: unusual manifestation of this rare disease.

Ichthyosis hystrix is a term used to describe an ichthyosiform dermatosis which is characterized by hyperkeratotic spiny scales mainly over extensor aspects of limbs with palmoplantar keratoderma and occasionally associated with deafness and neurological deficit. It is a rare autosomal dominant form of ichthyosis and very few cases are reported in literature. We are presenting a 46 years-old-male patient of ichthyosis hystrix with unusual presentation. He had lesions mainly over the face and scalp with palmoplantar keratoderma and significant nail changes.

What was known?

Ichthyosis hystrix is a rare case which was only once reported in India.

Introduction

Ichthyosis is a defect of keratinization presenting as dry, rough skin with scaling over much of the body. Ichthyosis hystrix is a type of congenital ichthyosis that clinically resembles epidermolytic hyperkeratosis with massive spiky or verrucous hyperkeratosis, erythema without blistering, mainly over the extensor aspect of the arms and legs.[1] It is inherited either as autosomal dominant or as sporadic variety.[2] Often the severity varies among the family members from only palmoplantar keratoderma to generalized involvement.[1] Palmoplantar keratoderma affects most of the patients and may be so severe that contracture, fissuring, nail dystrophy, or functional impairment may occur. With age, scaling may improve or stabilize.

We are reporting this case of ichthyosis hystrix due to its atypical presentation with severe involvement of face and scalp, skip areas over trunk, onychogryphosis of most of the nails, and a negative family history.

Case Report

A 46-year-old male patient presented with generalized severely thick skin since early childhood. According to his mother he was born normal and healthy. He gradually developed thickening of skin with adherent scales starting from face and progressively involving other parts of the body. None of the family members were affected. On examination, he had hyperkeratotic, thick, dry, adherent, mud-colored scales covering most of the body especially the face, scalp, and extremities including the flexures. Few areas had porcupine like spikes. Facial skin was so thickened and rugose that it became expressionless giving him a masked appearance [Figure 1]. His trunk was least involved with islands of normal skin [Figure 2]. Both, follicular prominence and atrophy were seen over the flexures of the forearm. He had associated nongradient palmoplantar keratoderma. Hairs were sparse and less over occipital area as it was covered with thick scale. He also had teeth and nail abnormality for the same duration. Most of the teeth were absent and canine was peg-shaped [Figure 1]. Subungual hyperkeratosis and prominent onychogryphosis were found in most of the nails [Figure 3]. There were no apparent ophthalmological or skeletal abnormalities, neither any hearing loss. His complete hemogram and chest X-ray were normal. On histopathology, we found orthokeratotic hyperkeratosis with sparse parakeratosis, irregular acanthosis, follicular plugging, and multiple binucleated keratinocytes in the epidermis along with upper dermal lymphocytic infiltrate, suggestive of ichthyosis [Figure 4 and 5]. On the basis of clinical features and histopathology, we arrived at the diagnosis of ichthyosis hystrix.

Figure 1

Thick confluent scales over face with teeth abnormalities

Figure 2

Areas of normal looking skin over trunk with flexural involvement

Figure 3

Onychogryphosis involving most of the finger nails

Figure 4

Hyperkeratosis, parakeratosis, acanthosis with upper dermal infiltrates (H and E, ×100)

Figure 5

Multiple binucleated keratinocytes in the epidermis (H and E, × 400)

Discussion

Ichthyosis hystrix is a type of congenital ichthyosis associated with many rare conditions and presenting as generalized and nevoid forms.[1] It was first documented in between 1731 and 1851 in the Lambert family of Suffolk. The word ‘hystrix’ means porcupine-like, describing the classical presentation. In addition to the extensors, flexures, and other sites of the body including scalp may be involved by mild scaling. Palmoplantar keratoderma affects most patients and often extend to the dorsal hands and when it is severe; fissures, contractures, nail dystrophy, and functional impairment may occur. Patient may present at birth or there may be a delayed onset in infancy or childhood.[3] Our patient presented with a childhood onset of generalized severely thickened mud-colored verrucous hyperkeratosis including involvement of flexures with severe palmoplantar keratoderma without any contracture or functional impairment. However, he had severe subungual hyperkeratosis and onychogryphosis in most of the nails. His face was affected the most and over trunk we found a few spared areas with normal looking skin. His scalp was also involved with very thick scales and loss of hair at the occipital area. There was no history of blistering throughout the duration. Ichthyosis hystrix occurs due to a defect in abnormal keratin expression in spinous keratinocytes. Ultrastructural abnormalities of disorganized keratin filament with normal epidermal proliferation rates are seen.[2] One study showed keratin mutation affecting V2 domain of keratin 1.[45] We had no facilities to do these tests in our institute. Ichthyosis hystrix includes Brocq, Lambert, Curth-Macklin, Rheydt and Bäfverstedt types.[6] In Lambert type, patients are alright at birth but develop dark warty scaling at the age of 7 weeks or later and face, palm, and soles were spared in those patients. Bäfverstedt type was reported by Bäfverstedt which was ichthyosis with striking hystrix scaling on the face. Patients presenting with severe palmoplantar keratoderma are diagnosed as ichthyosis hystrix of Curth-Macklin type.[3] Porcupine spine or symmetrical hystrix with scaling of dull brown color over extensor aspect of limb, trunk is also seen in the above type.[7] Connexin 26 defect causing hystrix-like ichthyosis deafness (HID) syndrome is a variant of ichthyosis hystrix which is also known as Rheydt type.[8] However, our patient had no hearing abnormality. Ichthyosis hystrix is also associated with skin malignancy.[9] Histopathology of epidermis shows severe orthohyperkeratosis, patchy parakeratosis, acanthosis, and papillomatosis with scattered vacuolated and binucleate keratinocytes.[1] In our case we also found hyperkeratosis, a small area of parakeratosis, acanthosis, and multiple binucleated keratinocytes. Treatment of severe generalized cases is difficult. As was advised in our patient, keratolytics and emollients are being used by patients of icthyosis hystrix to decrease the keratoderma and scaling. Systemic retinoids also showed some beneficial results.[10] Some studies also show surgical approach for treatment of icthyosis hystrix.[11]

We decided to report this case because of a few atypical features in the form of childhood onset, severe involvement of scalp, face and flexures, dental abnormalities, and severe nail involvement without contractures; and to the best of our knowledge, after extensive search in literature, this is the second case (first case was reported in Indian Journal of Dermatology[12] in 1975) to be reported from India.

What is new?

To the best of our knowledge it is only the second case being reported from India.

Our case also has unusual presentation of facial involvement along withflexural and scalp involvement.

The patient also had associated nail involvement in the form of onychogryphosis.