True about infantile tremor syndrome –
"Infantile tremor syndrome is a self-limiting disorder characterised by acute & gradual onset with neural & psychomotor changes, pigmentary disturbances of hair & skin, pallor & tremors".
Infants Tremor Syndrome 

Found in infants & young children
Etiological possibilities are malnutrition, Vit. B12 deficiency & viral infections but none have been conclusively proven.
Boys are twice as commonly affected as girls.
Most cases occur in summer months in children belonging to the low socioeconomic group.
There are 3 clinical phases - prodromal, tremor & post tremor phases.
There is hyperpigmentation, especialy over dorsum of hands, feet, knees ankles, wrists, terminal phalanges & thigh.
At times there may be fever, upper respiratory tract infection, diarrhoea, edema, hepatomegaly & a tremulous cry.
Tremor are coarse, fast, 6-12 cycles per second, of low amplitude, initially intermittent but become continuous later on.
There is mild to moderate pallor.
Pnenumoencephaly reveals cortical atrophy. CT scan shows no abnormalities or mild atrophy. - O.P. Ghai.
Subnormal intelligence is only long term sequele.
Treatment is largely empirical, symptomatic & supportive.
Hyperpigmentation of extremities
Cortical atrophy
Self limiting disorder
All of these