Vohwinkel's Syndrome: A Rare Disorder of Keratinization.

Sir,

Vohwinkel's syndrome is an autosomal dominant type of palmoplantar keratoderma characterized by honeycomb appearance, pseudoainhum leading to autoamputation, stellate keratosis on knuckles, and associated with mild sensorineural deafness.

It has been reported sparingly from all over the world.

A 16-year-old Muslim female born of a nonconsanguineous marriage and having no other affected sibling out of nine brothers and sisters, presented with honeycomb palmoplantar keratoderma [Figure 1a and b] which started since the age of 8 years. It progressed steadily and there was development of fibrotic bands around fingers and toes since the age of around 12 years. These bands subsequently lead to autoamputation of the little fingers of both hands and toes of both legs. There were starfish-like keratoses [Figure 1c] over the knuckles and hyperkeratotic papules over the dorsum of both feet. The histopathological findings consisted of marked hyperkeratosis, acanthosis, and focal hypergranulosis [Figure 2]. Hair and nails were normal.

Figure 1

(a) Palmar kertoderma with constricting bands. (b) Plantar kertoderma. (c) Starfish-like keratoses

Figure 2

Histopathology consisted of marked hyperkeratosis, acanthosis, and focal hypergranulosis

Though the patient did not have any complains of sensory deficit, we asked for an audiogram which revealed mild-to-moderate sensory neural deficits in both ears [Figure 3]. Another test including CT scan of brain, USG abdomen, routine blood reports, and barium swallow did not reveal any pathology. On the basis of these features, a diagnosis of Vohwinkel's syndrome was made.

Figure 3

Audiometry report showing sensorineural deafness

Before presenting to us, the patient was seen by different doctors without any active management which led to the advance progress of the disease and loss of fingers and toes. We started the patient on oral isotretinoin (20 mg/day) which led to significant improvement after 2 months of therapy with decreased keratoderma [Figure 4a and b] and arrest of the progression of fibrotic bands.

Figure 4

(a) Reduced thickness of starfish-like keratosis. (b) Reduced keratoderma after 2-month isotretinoin

In 1929, Vohwinkel first described this syndrome in a 24-year-old woman who had a diffuse honeycombed palmar and plantar keratosis, in addition to distal interphalangeal constrictions since 2 years of age. The constrictions ultimately led to auto-amputation. The daughter of this patient experienced similar clinical lesions. The patient also had mild-to-moderate sensorineural deafness.

Vohwinkel syndrome also known as “keratoderma hereditaria mutilans” and “mutilating palmoplantar keratoderma” is a rare autosomal dominant disorder although few sporadic cases have also been described. No racial and sex predominance is reported. The lesions start appearing in infancy or early childhood and gradually progress with age.

Two types of mutations of epidermal differentiation have been identified in Vohwinkel syndrome.

One is a novel missense mutation of the GJB2 gene (gap junction protein beta 2) coding connexin-26, a gap junction protein.[12] This mutation is associated with the classic, sensorineural hearing loss-associated Vohwinkel syndrome.

Another mutation is an insertional mutation of the loricrin gene on the epidermal differentiation complex on 1q21. A phenotype associated with ichthyosis and not deafness is observed.[3]

An ichthyotic variant with a 730insG mutation[4] has recently been described.

A case report described a new variant of Vohwinkel syndrome with congenital hypotrichosis[5] in two siblings.

A novel missense mutation in GJB2, p. Tyr65His is found to be associated with severe Vohwinkel syndrome.[6]

Because of the rare occurrence of this syndrome, many treatment modalities are not described. Topical treatment is usually not sufficient. Keratolytics like salicylates and urea and topical retinoids can reduce keratoderma. Etretinate was first used for Vohwinkel's syndrome in 1981. Systemic retinoids can reverse keratoderma and pseudoainhum; however, relapse can occur on discontinuation of the drug.[78]

Surgical release of the constriction bands in the form of z-plasty or cross finger flap have been described to preserve the digits.[9]

We here report a case of Vohwinkel syndrome which has been described very sparingly from this part of the world. While working up the case we faced the limitation of access to genetic analysis in a resource-poor set-up. For that reason we could not identify the mutation. We also presume that our case is a sporadic case as there was no clinical evidence of vertical transmission; neither there was any history of consanguinity. But, we understand that in the absence of genetic analysis of the case and her parents, it is difficult to conclusively establish the mode of transmission.

Apart from the rarity of the cases, we also emphasize that judicious use of oral retinoids may save the patient from ainhum, auto-amputation, and eventual disability.