Differential Diagnosis for Hypopigmentation and Ocular Clonus
- Single most likely diagnosis:
- Tuberous Sclerosis Complex (TSC): This genetic disorder is known for causing hypopigmented skin lesions (ash-leaf spots) and can also lead to ocular manifestations, including ocular clonus due to retinal hamartomas. The combination of skin and eye findings makes TSC a strong candidate.
- Other Likely diagnoses:
- Neurofibromatosis Type 1 (NF1): While more commonly associated with hyperpigmentation (café-au-lait spots), NF1 can occasionally present with hypopigmented lesions. Ocular clonus is not a typical feature but can occur in the context of optic gliomas or other CNS involvement.
- Waardenburg Syndrome: This syndrome is characterized by congenital deafness, minor defects in the structures arising from the neural crest, and pigmentation abnormalities, including hypopigmentation. Ocular findings can include heterochromia of the iris, which might be associated with abnormal eye movements.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Subacute Sclerosing Panencephalitis (SSPE): A rare but fatal complication of measles infection, SSPE can cause a variety of neurological symptoms, including myoclonus and ocular abnormalities. Hypopigmentation is not a primary feature, but the severity of SSPE warrants its consideration.
- Metastatic Disease: In rare cases, metastatic cancer can cause both skin and ocular manifestations, including hypopigmentation (due to metastasis to the skin) and ocular clonus (due to brain or orbital metastasis).
- Rare diagnoses:
- Vogt-Koyanagi-Harada Disease: An autoimmune condition that can cause uveitis, skin depigmentation (vitiligo), and neurological symptoms. While it's a rare condition, the combination of hypopigmentation and ocular symptoms could fit this diagnosis.
- Cross-McKusick-Breen Syndrome: A very rare genetic disorder with features including hypopigmentation, ocular abnormalities, and sometimes neurological symptoms. Given its rarity, it's less likely but should be considered in the differential diagnosis of complex cases.