Phacomatosis pigmentokeratotica: a follow-up report with fatal outcome.

Phacomatosis pigmentokeratotica (PPK) was first described in 1996 (1) as a distinct disease characterised by coexistence of a large sebaceous naevus and speckled len-tiginous naevus of the papular type. It can be associated with musculoskeletal, neurological and ophthalmological abnormalities (2). This is a follow-up report of a boy previously reported with grave extracutaneous abnormalities (3) who subsequently died of severe complications. Six years ago, a premature boy was born at 34 weeks of gestation with multiple flesh-coloured verrucous plaques on his limbs, chest, back and both sides of the scalp and face along Blaschko's lines. The large and confluent patches and plaques gradually darkened and became raised with multiple papular speckles (Fig. 1). Two skin biopsies from the aforementioned lesions showed sebaceous naevus and melanocytic naevus, and PPK was diagnosed. After 5 years, these plaques had darkened and become more prominent, and papular speckles increased in number, with few fine vellus hair on his scalp (Fig. 2). He had multiple prematurity complications: retinal haemorrhage, neonatal jaundice and patent ductus arteri-osus. Since 5 months of age, he suffered from recalcitrant status epilepticus; only valproic acid and nitrazepam were effective early in the course of epilepsy. Visual impairment was also noticed. An ophthalmological examination conducted by flash visual evoked potential showed normal latency but decreased amplitude over the occipital region, suggesting a bilateral retrochiasmatic problem. A brain echogram showed some ventriculomegaly and relative thinning of the corpus callosum. Mild right-sided hearing loss was confirmed by an audiobrainstem reflex test (ABR). He had severe musculoskeletal deformities, including underdeveloped teeth, scoliosis, low muscle power, and hypophosphataemia that was resistant to vitamin D treatment. The recalcitrant hypophos-phataemia made him ricket-like in appearance. Significant retardation in growth and development had also been noted since he was 4 months old (3). Malignant tumours from the skin or internal organs were absent. However, he had been hospitalised frequently; he was malnourished since birth by poor digestive function and chronic diarrhoea. At the age of 2, biopsy of the stomach and duodenum indicated chronic inflammation and moderate villous atrophy. His teeth were underdeveloped with gingival enlargement over the right side of his mouth when he was 3 years old. At the age of 6, intractable hypo-albuminaemia (albumin, <3 g/dl), hypokalaemia (potassium , 2.5 mmol/l) and hypophosphataemia (phosphate, 1.3 mg/dl) could not be corrected by nasogastric tube feeding and necessitated total parenteral nutrition. Severe anaemia (haemoglobin, <9 g/dl) persisted, necessitating …