Skin color can range from bright red in patients with acute conditions to pale violet or brown in those whose conditions are chronic. Erythema must be differentiated from purpura, which causes redness from bleeding into the skin.
Causes:
Allergic reactions:
Foods, drugs, chemicals, and other allergens can cause an allergic reaction and erythema. A localized allergic reaction also produces hivelike eruptions and edema.
Anaphylaxis, a life-threatening reaction, produces relatively sudden erythema in the form of urticaria. It also produces flushing; facial edema; diaphoresis; weakness; sneezing; bronchospasm with dyspnea and tachypnea; shock with hypotension and cool, clammy skin; and possibly airway edema with hoarseness and stridor.
Burns:
In thermal burns, erythema and swelling appear first, possibly followed by deep or superficial blisters and other signs of damage that vary with the severity of the burn. Burns from ultraviolet rays, such as sunburn, cause delayed erythema and tenderness on exposed areas of the skin.
Candidiasis:
When this fungal infection affects the skin, it produces erythema and a scaly, papular rash under the breasts and at the axillae, neck, umbilicus, and groin (intertrigo). Small pustules commonly occur at the periphery of the rash
Cellulitis:
This bacterial infection of the skin and subcutaneous tissue causes erythema, tenderness, and edema.
Dermatitis:
Erythema commonly occurs in this family of inflammatory disorders. In atopic dermatitis, erythema and intense pruritus precede the development of small papules that may redden, weep, scale, and lichenify. These occur most commonly at skin folds of the extremities, neck, and eyelids.
Erysipelas:
This skin infection caused by group A beta-hemolytic streptococci is characterized by an abrupt onset of reddish, well-demarcated, tender, warm, sometimes elevated lesions, mainly on the face and neck but sometimes also on the extremities. Flaccid, pus-filled bullae may develop after 2 to 3 days. Extension into deeper tissues is rare. Other signs and symptoms include fever, chills, cervical lymphadenopathy, vomiting, headache, sore throat, warmth and tenderness in the affected area and, possibly, alopecia.
Erythema multiforme:
This acute inflammatory skin disease develops as a result of drug sensitivity after an infection most commonly herpes simplex or a mycoplasmal infection, allergies, or pregnancy. One-half of the cases are of idiopathic origin.
Frostbite:
First-degree frostbite turns the affected body part a lifeless gray color, followed by an intense bluish red flush on re warming. Blisters, lack of feeling, and tissue necrosis may follow.
Liver disease (chronic):
Any chronic liver disease, such as cirrhosis, can cause local vasodilation and palmar erythema along with jaundice, pruritus, spider angiomas, xanthomas, and characteristic systemic signs.
Staphylococcal scalded skin syndrome:
This endotoxin-mediated epidermolytic disease is caused by a clinically unapparent Staphylococcus aureus infection and primarily affects infants (Ritter's disease) and small children. It's characterized by erythema and widespread exfoliation of superficial epidermal layers, resembling scalded skin. Associated signs and symptoms include low-grade fever and irritability.
Radiation and other treatments:
Radiation therapy may produce dull erythema and edema within 24 hours. As the erythema fades, the skin becomes light brown and mildly scaly. Any treatment that causes an allergic reaction can also cause erythema.
Investigations:
1. Complete blood picture
2. Liver function tests
3. Complete urine analysis
4. Skin sensitivity tests
Homoeopathic approach:
Belladonna:
Belladonna is perhaps more frequently indicated in commencing erysipelas than any other remedy and it is often specific.
The erysipelas corresponding to Belladonna is of the smooth variety; the skin is shining and tense and dark red or bright red, the swelling is rapid and there are sharp, lancinating pains or throbbing in the parts.
Accompanying this condition there is throbbing headache, fever , delirium, swollen glands and tenseness of the parts. It may occur on the scalp, face
Rhus tox:
This remedy corresponds to the vesicular variety; the skin is dark, covered with vesicles.
It is especially adapted to erysipelas attacking the scalp, skin of face, or genital organs.
It has shivering followed by high fever; there is intense headache.
The cause of the trouble calling for Rhus may be exposure to cold or getting wet.
Apis mellifica:
The erysipelas of this remedy is of a rosy pink hue at first, later becoming livid and purple as the oedema which is characteristic of the drug appears.
The oedema appears quickly and the parts feel sore and bruised. It is especially indicated where the disease spreads from a hard centre.
Umbilical erysipelas in children, stinging pains, urine suppressed and no thirst.
Lachesis:
Erysipelas commencing on the left side and spreading to the right, at first bright red, then dark bluish or purplish.
The cellular tissues are especially involved and infiltrated.
The patient is drowsy, has a delirium which is perhaps loquacious and the parts affected threaten gangrene.