Medical Term for Slightly Purple
The medical term for a slightly purple color is "purpura" or more specifically "violaceous" when describing a purple-red hue in clinical dermatology. 1
Types of Purple Discoloration
- Purpura refers to purple-colored spots or patches on the skin caused by bleeding underneath the skin, typically seen in thrombocytopenic conditions or vasculitis 2, 3
- Violaceous specifically describes a purple-red or violet-colored appearance, often used to characterize skin lesions in various dermatological conditions 2, 1
- Dusky erythema describes a darker red to purple discoloration that may be seen in conditions like Stevens-Johnson syndrome/toxic epidermal necrolysis 2
Clinical Significance of Purple Discoloration
Thrombocytopenic Purpura
- Purple discoloration due to low platelet count (typically <30,000) is a hallmark of thrombocytopenic purpura 1, 3
- Peripheral blood smear examination is essential for diagnosis, showing normal red and white blood cell morphology with decreased platelets 3
- Treatment depends on severity - observation for platelet counts >30,000 with minimal symptoms, while counts <20,000 with significant bleeding require intervention 3
Vasculitic Purpura
- Characterized by palpable purpuric lesions due to inflammation of blood vessels 1, 4
- Often associated with systemic symptoms such as fever, arthralgia, and organ involvement 1
- Skin biopsy is crucial for diagnosis, with samples taken from the edge of a lesion 5
Other Purple Discolorations
- Purple toe syndrome - a rare complication of vitamin K antagonist therapy (like warfarin), characterized by purple lesions on toes and sides of feet 2
- Perniosis - cold-induced painful or pruritic erythematous or violaceous acral lesions 6
- Atypical pigmentary purpura - characterized by superficial dermal lymphocytic infiltrates and hemorrhage 7
Diagnostic Approach
- Complete blood count with platelet count is the essential first test for suspected thrombocytopenic purpura 3
- Peripheral blood smear examination to confirm thrombocytopenia and exclude other causes 3
- For palpable purpura, additional testing may include coagulation studies, autoimmune markers, and infectious disease testing 1, 5
- Skin biopsy with both H&E and direct immunofluorescence studies is recommended for definitive diagnosis of many purpuric conditions 5
Clinical Pearls
- Purple discoloration in Stevens-Johnson syndrome/toxic epidermal necrolysis appears as dark red or dusky lesions that may blister and coalesce 2
- Midline and lumbosacral infantile hemangiomas (which may appear purplish) can be associated with underlying spinal dysraphism 2
- Drug-induced purpuric eruptions can occur with medications including calcium channel blockers, lipid-lowering agents, beta-blockers, and cytarabine 7, 8
- The distribution pattern of purpuric lesions can provide diagnostic clues - acral distribution may suggest perniosis, while retiform patterns may indicate vascular occlusion 5, 6