What is in the Differential Diagnosis for Green, Blue or Violet Skin Conditions?

Patient Presentation
A term, newborn male was seen in the newborn nursery and the history was non-contributory. The pertinent physical exam showed a healthy male with a weight of 3367 grams. He had molding of his head, mild acrocyanosis and blue melanocytosis across his buttocks and upper posterior thighs. The diagnosis of a a healthy male was made who was transitioning to external life normally with acrocyanosis. He had routine care and was discharged at 2 days of life.

Acrocyanosis is commonly seen in the newborn period as the baby transitions to extra-uterine life. It appears as blue-purple coloration of the distal extremities which usually improves over several hours.
Blue melanocytosis is also a common normal variant of skin color. It usually is seen on the posterior surface of the body around the spine and buttocks, but can also be on the upper parts of the extremities.
It is a blue-black coloration that shows a normal skin undertone when palpated.

This is the second in a short case series of differential diagnoses of colored skin conditions.
An introduction to dermatological terminologies and information about colors can be can be found here.
A differential diagnosis by distribution and common pattern can be found here.
For red, orange and yellow conditions, a review can be found here.
For black and white conditions, a review can be found here.
For brown and grey conditions, a review can be found here.

Note that any color can be a normal variant for an individual or is physiologic for a given state.

Learning Point
Green is in the visible spectrum of light with wavelengths ranging from 500-565 nm.
The differential diagnosis for green skin conditions includes:

  • Skin
    • Bruising/ecchymosis
    • Apocrine chromhidrosis
    • Chlorosis – a review can be found here
    • Copper-induced green skin
    • Liver disease
    • Organ failure
    • Weil’s syndrome
    • Neoplasms – chloroma
    • Drugs
    • Infectious – Pseudomonas infections
    • Staining – tattoo
  • Hair
    • Green hair
      • Copper deposition
      • Chemicals and shampoos
      • Sun-bleaching
  • Nails
    • Chloronychia or green nail syndrome

Blue is in the visible spectrum of light with wavelengths ranging from 450-485 nm.
The differential diagnosis for blue skin conditions includes:

  • Skin
    • Alkaptonuria
    • Bruising/ecchymosis
    • B12 deficiency
    • Drug-induced
    • HIV infection
    • Iron deficiency
    • Livido reticularis
    • Methemoglobinemia
    • Myasthenia gravis
    • Necrotizing fasciitis
    • Osteogenesis imperfecta
    • Pernicious anemia
    • Physiologic
      • Newborn
      • Post-mortem
    • Radiation
    • Staining
      • Chemical-induced including many cleaners
      • Ink
      • Tattoo
    • Syndromes
      • Blue rubber bleb nevus
      • Ehler-Danlos syndrome
      • Kabuki syndrome
    • Tumors
      • Blue nevus
      • Carcinoma
      • Dermal melanocytosis (previously known as Mongolian spots)
      • Dermatofibroma
      • Eccrine angiomatous hamartoma
      • Hidrocystoma
      • Junctional nevus
      • Lymphoma
      • Melanoma
      • Nevus of Ota
      • Pilomatricoma
      • Spitz nevus (pigmented)
      • Metastatic malignancies
    • Vascular
      • Acrocyanosis
      • Cyanosis
      • Hemangiomas
      • Hematoma
      • Varicosities
      • Venous malformations
    • Wilson disease
  • Hair
    • Chemical-induced
  • Nails
    • Chemical-induced
    • Myxoid cyst
  • Mucosa
    • Mucocoele

Violet is in the visible spectrum of light with wavelengths ranging from 380-450 nm.
The differential diagnosis for violet skin conditions includes:

  • Skin
    • Arthropod bites
    • Bruising and ecchymosis
    • Connective tissue diseases
      • Dermatomyositis
      • Lupus erythematosis
      • Sjorgren syndrome
    • Contact dermatitis
    • Drugs – including contaminants
    • Staining – tattoo
    • HematologicThrombocytopenia
      • Platelet dysfunction
      • Thrombocytopenia
    • InfectionsThrombocytopenia
      • Disseminated intravascular coagulation
      • Purpura fulminans
      • Emboli – septic emboli
    • Neoplasms – metastatic disease
    • Vasculitis Thrombocytopenia
      • ANCA-associated vasculitis
      • Anti-phospholipid antibody syndrome
      • Erythema multiformae
      • Calciphylaxis
      • Cryoglobinemia
      • Eosinophilic granulomatosis with polyangiitis
      • Granulomatosis with polyangiitis (formerly Wegener’s granulomatosis)
      • IgA vasculitis (formerly Henoch-Schonlein purpura)
      • Thrombotic thrombocytopenic purpura
      • Microscopic polyangiitis
      • Necrosis
      • Polyarteritis nodosa
  • Hair
    • Chemical-induced
  • Nails
    • Chemical-induced
    • Emboli
  • Mucosa
    • Similar to skin

Questions for Further Discussion
1. What green skin conditions do you see often?
2. What blue skin conditions do you see often?
3. What violet skin conditions do you see often?
4. What are indications for referral to a dermatologist?

Related Cases

    Symptom/Presentation: Rash

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Rashes

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Ghosh SK, Bandyopadhyay D. The color of skin: green diseases of the skin, nails, and mucosa. Clinics in Dermatology. 2019;37(5):516-519. doi:10.1016/j.clindermatol.2019.07.012

Cohen PR. The color of skin: blue diseases of the skin, nails, and mucosa. Clinics in Dermatology. 2019;37(5):468-486. doi:10.1016/j.clindermatol.2019.07.006

Steuer AB, Cohen JM. The color of skin: purple diseases of the skin, nails, and mucosa. Clinics in Dermatology. 2019;37(5):528-547. doi:10.1016/j.clindermatol.2019.07.016

Visible spectrum. In: Wikipedia. 2021. Accessed January 4, 2022. https://en.wikipedia.org/w/index.php?title=Visible_spectrum&oldid=1062416030

Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa