A Case of Nasu-Hakola Disease without Fractures or Consanguinity Diagnosed Using Exome Sequencing and Treated with Sodium Valproate

Nasu-Hakola disease (NHD) is a rare autosomal recessive neuropsychiatric disorder characterized by bone cysts, fractures, and cognitive impairment. Two genes are responsible for the development of NHD; TYROBP and TREM2. Although it presents with typical signs and symptoms, diagnosing this disease remains difficult. This case report describes a male with NHD with no family or past history of bone fractures who was diagnosed using exome sequencing. His frontal lobe psychiatric symptoms recovered partially following treatment with sodium valproate, but not with an antipsychotic.

Pigmentation by transdermal fentanyl patch

<b>Introduction</b>: There has been no case report in which hyperpigmentation developed on the skin area where a transdermal fentanyl patch was applied in a patient. <b>Case report</b>: A 43-year-old man with recurrence of postoperative rectal cancer was treated by cetuximab plus irinotecan and panitumumab plus FOLFIRI. For cancer pain, transdermal fentanyl patch (Fentos®) was administered, and radiation from behind was performed. Hyperpigmentation then appeared on the chest and the abdominal skin sites where the patches were applied. The hyperpigmentation nearly disappeared four months after the fentanyl patch was discontinued. <b>Discussion</b>: The cause of the pigmentation was possibly due to post inflammatory hyperpigmentation secondary to contact dermatitis. It was desirable to conduct patch test and skin biopsy for making an accurate diagnosis. <b>Conclusion</b>: We should pay a careful attention to hyperpigmentation of the skin where a transdermal fentanyl patch is applied.