cyanotic hands or peripheral cyanosis or blue hands at asian child with congenital heart disease

blue bluish breathless breathlessness cardiac central changes child chronic color covid cyan cyanosis cyanotic dark discoloration discolored discolouration discoloured disease disorder finger fingers fingertips hand hands heart hypoxemia hypoxia ill illness kid lung nails omicron paediatric palm palmar patient peripheral purple respiratory skin smoker smoking stain stained unhealthy