What are the six colour diseases? A clarification
The phrase "the six colour diseases" is a catchy but medically inaccurate term used to group various conditions based on the prominent skin or organ colour changes they produce. There is no single, defined list of six such diseases. Instead, a host of different medical issues can manifest with similar colour-related symptoms. Addressing these colour changes individually provides a clearer, more accurate understanding of what they may signify.
The meaning behind the colours
Red Skin
Redness of the skin, medically known as erythema, is commonly caused by inflammation. It occurs when small blood vessels near the skin's surface widen, increasing blood flow to the affected area. Causes range from eczema and psoriasis to infections like cellulitis or scarlet fever, allergic reactions, and autoimmune diseases such as lupus.
Yellow Skin
Jaundice, a yellowish discolouration of the skin and eyes, results from excess bilirubin, a pigment from red blood cell breakdown. It often indicates liver issues like hepatitis or cirrhosis, bile duct obstruction, or blood disorders like hemolytic anemia.
Green Skin
Historically, chlorosis or "green sickness" was linked to iron-deficiency anemia in young women. Today, green skin is less common and can be due to resolving bruises, bacterial infections like Pseudomonas aeruginosa, or localized copper exposure.
Blue Skin
Cyanosis, a bluish tint, signifies low oxygen in the blood. This is often serious and can be caused by heart problems like congenital defects or failure, lung issues such as severe pneumonia or pulmonary embolism, airway obstruction, or environmental factors like high altitude or cold.
Purple Skin
Purple patches called purpura are caused by bleeding from small blood vessels under the skin and don't fade when pressed. Causes include weakened blood vessels from age (senile purpura), inflammation (vasculitis), or clotting disorders (thrombocytopenic purpura). Low oxygen can also appear purplish on some skin.
White Skin
White skin patches, or hypopigmentation, occur when skin loses melanin. This can be due to vitiligo, an autoimmune disease destroying pigment cells, albinism (a genetic condition), fungal infections like tinea versicolor, or a mild form of eczema called pityriasis alba.
Comparison of skin colour-related health issues
| Colour | Associated Condition(s) | Primary Cause | Severity |
|---|---|---|---|
| Red | Rosacea, cellulitis, lupus, rashes | Inflammation, infection, autoimmune response | Varies from minor irritation to severe infection |
| Yellow | Jaundice (Hepatitis, liver disease), hemolytic anemia | Excess bilirubin from red blood cell breakdown or liver dysfunction | Can be a sign of serious liver disease or cancer |
| Green | Chlorosis (iron-deficiency), Pseudomonas infections, bruising | Low hemoglobin, bacterial infection, decomposing blood pigments | Historical anemia or specific infections |
| Blue | Cyanosis (Congenital heart disease, pulmonary embolism) | Insufficient oxygen supply in the blood | Often an emergency medical condition |
| Purple | Purpura (Vasculitis, clotting disorders, Henoch-Schönlein) | Bleeding from small blood vessels under the skin | Varies; can indicate a serious clotting disorder |
| White | Vitiligo, albinism, tinea versicolor, pityriasis alba | Loss of skin pigment (melanin) due to autoimmune, genetic, or fungal causes | Cosmetic to potentially linked with other autoimmune conditions |
Conclusion: Seeking professional medical advice
The idea of "the six colour diseases" is a non-medical concept. Skin colour changes are symptoms of various health issues, ranging from minor to life-threatening. Persistent or unexplained changes, especially with other symptoms like difficulty breathing, fever, or pain, require immediate medical attention for proper diagnosis and treatment. Reliable information on specific conditions can be found from organizations like the Cleveland Clinic, Mayo Clinic, or the National Institutes of Health.
