Comprehensive Guide- Cyanosis: Blue Discoloration of skin

What is Cyanosis (Blue Discoloration of Skin)?

According to Wikipedia,

Cyanosis is the change of body tissue color to a bluish-purple hue, as a result of decrease in the amount of oxygen bound to the hemoglobin in the red blood cells of the capillary bed. Cyanosis is apparent usually in the body tissues covered with thin skin, including the mucous membranes, lips, nail beds, and ear lobes.

Overview

What is Cyanosis?

Cyanosis is the medical term for when your skin, lips or nails turn blue due to a lack of oxygen in your blood. If you have darker skin, cyanosis may be easier to see in your lips, gums, nails and around your eyes. The word cyanosis comes from the word cyan. Cyan is a blue-green color.

Normally, red blood cells carry oxygen to the tissues in your body. Your blood is red when it’s filled with oxygen because your blood cells are bright red. As a result, when oxygen-filled blood circulates throughout your body, your skin has a pink or red tone.

When there’s not enough oxygen circulating in your blood, it’s darker and more of a blue or purple tone. The area of your body that’s most affected by cyanosis can help determine the cause.

What are the different types of cyanosis?

The three types of cyanosis are circumoral (perioral), peripheral and central.

Circumoral (perioral) cyanosis

Circumoral cyanosis is when only your mouth or lips turn blue. It often occurs when your blood vessels shrink in response to cold temperatures. Circumoral cyanosis is common — and can be normal— in newborns. In older children, it may appear when they go outside in cold weather.

Peripheral cyanosis

Peripheral cyanosis is when only your hands, fingers, feet and/or toes turn blue. This can happen in very cold weather if your hands and feet aren’t well protected. It’s rarely life-threatening, but it’s important to find out the cause because it may need quick treatment to prevent permanent injury.

Central cyanosis

Central cyanosis is when other parts of your body are affected in addition to your hands and feet. This may include your chest, cheeks, tongue, gums and lips. Serious heart, lung or blood conditions may be the cause of central cyanosis. It’s very important to seek treatment immediately.

Differential diagnosis

Central cyanosis in neonates

Central cyanosis should clear within a few minutes of the birth. Peripheral cyanosis clears within a few days. Increased sensitivity of the peripheral circulation to cold temperature may persist well into infancy.

• Transient cyanosis after delivery can occur without clear diagnosis. One study suggested that a significant proportion may have gastro-oesophageal reflux.
• Cardiac and circulatory causes include:
• Transposition of the great arteries.
• Fallot’s tetralogy.
• Stenosis or atresia of the pulmonary valve or tricuspid valve.
• Total anomalous pulmonary venous return (all four pulmonary veins drain into systemic veins or the right atrium, associated with a right-to-left shunt through an atrial septal defect.
• Hypoplastic left heart.
• Truncus arteriosus (a single great artery leaves the heart and divides into the pulmonary artery and the aorta).
• Persistent fetal circulation (blood continues to be shunted through the foramen ovale and a patent ductus arteriosus).
• Respiratory causes include:
• Respiratory distress syndrome.
• Birth asphyxia, birth injury or haemorrhage.
• Transient tachypnoea of the newborn.
• Pneumothorax.
• Meconium aspiration.
• Pulmonary oedema.
• Congenital diaphragmatic hernia.
• Tracheo-oesophageal fistula.
• Pleural effusion.
• Obstruction of the upper respiratory tract – for example, in Pierre Robin sequence or choanal atresia.
• Other causes include infection, seizures and metabolic abnormalities – eg, hypoglycaemia, hypomagnesaemia.

Central cyanosis in adults

• Lung disease: any severe respiratory disease, pulmonary oedema, pulmonary embolism, decreased PO2 of inspired air (eg, high altitude), severe pneumonia, chronic obstructive pulmonary disease (COPD), acute severe asthma, acute adult respiratory distress syndrome.
• Right-to-left cardiac shunt: eg, cyanotic congenital heart disease, Eisenmenger’s syndrome, pulmonary arteriovenous fistulas.
• Abnormal haemoglobins (do not allow adequate oxygen uptake):
• Methaemoglobinaemia: may be genetic or associated with certain drugs – eg, quinones, primaquine, sulfonamides.
• Sulfhaemoglobinaemia: is usually associated with certain drugs, especially sulfonamides.
• Polycythaemia vera or any other cause of polycythaemia may present with central cyanosis.

What are the symptoms of cyanosis?

The main symptom of cyanosis is a bluish discoloration of your skin. The bluish tone may also affect your lips, tongue, gums, ears and nails.

If you have darker skin, cyanosis may look more gray or white. It may also show up more around your lips, tongue, gums, nails and eyes.

Cyanosis is typically caused by another condition. Depending on what’s causing the cyanosis, other symptoms you may experience include:

• Low body temperature (hypothermia).
• Numbness or tingling in your arms and legs.
• Coughing.
• Wheezing.
• Difficulty breathing.
• Difficulty breathing.
• Extreme tiredness (fatigue).
• Weakness.

What does cyanosis signify?

Cyanosis can mean your organs, muscles and tissues aren’t getting the amount of blood they need to function properly. Many different conditions can cause cyanosis. While blue skin and lips aren’t always a cause for concern, some conditions do need immediate medical treatment. Conditions causing cyanosis may be related to your lungs, heart or central nervous system.

What causes cyanosis?

Cyanosis is usually caused by a lack of oxygen in your blood. This may be because your blood doesn’t have enough oxygen in it, or because blood vessels are exposed to cold temperatures. Circulating blood keeps your organs and body parts warm. But if it’s very cold out, the blood vessels in your hands, feet and ears clamp down to keep your body temperature normal.

Many conditions can cause your blood to lack the oxygen it needs.

Airway problems

• Choking (suffocation).
• Swelling around your vocal cords (croup).
• Inflammation of the flap in your throat that covers your windpipe (epiglottitis).

Lung problems

• High altitudes.
• Asthma.
• Infection in your respiratory tract.
• Blood clot in an artery of your lung (pulmonary embolism).
• Chronic obstructive pulmonary disease (COPD).
• Pulmonary hypertension.
• Pneumonia.

Heart problems

• Heart defects that were present at birth (congenital heart defects), such as double outlet right ventricle and tetralogy of Fallot.
• Congestive heart failure.
• Cardiac arrest.

Other causes of cyanosis

• Wearing clothes that are too tight and limit your circulation.
• Exposure to extreme cold.
• Raynaud’s phenomenon, a disorder that causes your blood vessels to narrow.
• Medications that are used to treat high blood pressure.
• Seizures.
• Drug overdose.
• Toxic exposures.

Diagnosis