Post Herpes Zoster Trigeminal Trophic Syndrome in a Child.

Sir,

A 7-year-old child was brought to the dermatology outpatient clinic with complaints of ulceration and scarring involving right side of face. The patient had complaints of dysesthesia and itching involving right side of face after episode of herpes zoster involving trigeminal nerve distribution 3 months back. The episode of herpes zoster was treated with acyclovir at 80 mg/kg in divided doses along with analgesics and subsequently lesions healed with scarring. On examination, the patient had scars present over right side of his face in trigeminal nerve distribution. The patient also had discrete ulcers over right side of face over chin and pre-auricular region. The ulcers were crescent in shape and were measuring 1 × 0.8 cm and 0.8 × 06 cm in size, respectively [Figure 1]. The Gram stain, Tzanck smear and pus culture examination did not yield any abnormality. Rest of examinations were non-contributory.

Figure 1

Clinical photograph showing post herpes zoster scar and trophic ulcers in pre auricular, cheek and chin region of right side of face

Trigeminal trophic syndrome (TTS) is an uncommon disorder, characterized by the triad of trigeminal anesthesia, facial paresthesia and ulceration of the lateral nasal ala. It is usually seen in elderly patients with a predilection for women.[1] The ulcers usually develop within 2 years of trigeminal nerve injury but the period may vary from several weeks to many years.[1] Pediatric TTS is all the more rare, with only a few previously reported cases in the literature,[1234] listed in Table 1.

Table 1

Pediatric trigeminal trophic syndrome cases reported in the literature

TTS is reported to occur following injury to sensory branches of trigeminal nerve or its central connections. The various diseases implicated include meningioma affecting trigeminal nerve, complication of encephalitis, stroke, trauma or iatrogenic (craniotomy/birth trauma).[125] The peripheral causes include Bell's palsy, infections such as leprosy, syphilis, herpes simplex and herpes zoster.[2] In our case, the patient had a history of herpes zoster, suggesting its possibility for the etiology of trigeminal nerve damage.

These patients generally complain of picking, rubbing or scratching sensations in the affected areas, which are attributed to hypoesthesia, paraesthesia, or pain following damage of the sensory trigeminal fibers. The ulcerations seen are characteristically unilateral, crescents shaped and are self-induced.[1] In severe cases, ulceration may be seen over jaw, forehead, cheek and lip.

TTS is a rare cause of chronic facial ulceration. Parasitic, fungal, viral, and tuberculous infections, neoplasms (squamous and basal cell carcinomas), vasculitis (Wegener granulomatosis), pyoderma gangrenosum must be considered in the differential diagnosis. Similar lesions may occur with factitial ulcer and as a result of battered baby syndrome too.[5] It, however, differs from dermatitis artefacta or compulsive skin picking as there is an identifiable neurological abnormality. Parents’ insensitiveness towards child and inconsistent history are helpful in predicting battered baby syndrome. Thus, detailed history (children and parents), astute cutaneous and sensory examination as well as psychological evaluation of both children and parents are required to conclude the diagnosis. In addition, few cases might require extensive work up including microbiological, histopathological, radiological and immunological investigations to rule out other causes of chronic facial ulceration.

The treatment is multifaceted, involving behavior modification for self-induced injury, oral psychotropic medications to decrease the paresthesias, occlusive dressings to block mechanical trauma, topical antibiotics to prevent wound infection and surgical intervention, if severe.[15] Educating the patient on their primary role in the pathogenesis of this disorder is paramount, and comes out to be a challenge especially in children.

Medical treatments used include carbamazepine, oxcarbazepine, amitriptyline, pregabalin, diazepam, clonazpam, chlorpromazine and pimozide.[12] Less commonly, surgical reconstruction and transcutaneous electrical nerve stimulation may be used as treatment regimens.[2] In our case, the child was prescribed topical antibiotics and occlusive dressings. In addition, the child and the parents were counseled for behavioral modifications. The ulcers healed in next few days. Subsequently, the patient was lost to follow up, with no complaints of new ulcers till the last visit.

The current case is a unique case of TTS in a child developing as a result of herpes zoster infection and outlines the diagnostic challenges of the syndrome in children.