Eruzioni cutanee

How are skin rashes described?

Skin rashes can be described in the following way:

• Redness of the skin (called eritema).

• Flat abnormally coloured areas of skin (called macules). Macules are often either red, dark red or purple, brown or white.

• Solid raised areas which are up to half a centimetre across (called papules).

• Solid raised areas which are more than half a centimetre across (called nodules).

• Areas of red raised skin (called plaques) e scales, which have a flaky silvery-white appearance.

• Reddish-purple lesions which do not fade with pressure (called porpora):
  

  • If less than one centimetre across then these are called petechiae.

  • If more than one centimetre across then they are called ecchymoses.

• Blisters: these are swellings of the skin containing fluid:

  • If a blister is less than half a centimetre across then it is called a vesicle. If filled with yellow fluid (pus) then it is called a pustule.

  • If a blister is larger than half a centimetre across it is called a bulla (plural is bullae).

Skin disorders that can cause itching include (please click the links to separate leaflets which provide further information):

• Pelle secca.

• Eczema.

• Contact dermatitis.

• Urticaria.

• Lichen planus.

• Psoriasi.

• Folliculitis.

• Prickly heat/heat rash.

Please click the links to separate leaflets which provide further information:

Red (erythema) but not scaly skin rash

• A skin infection called cellulite.

• An allergic reaction called orticaria.

• Reaction to a medicine you are taking.

• Ustioni.

• Eruzioni virali - ad esempio, morbillo o rubella (German measles).

• Vasculitis. This is a condition involving inflammation of blood vessels, which may occur with various illnesses, including artrite reumatoide.

• Eritema nodoso. This is a condition which causes red rounded lumps (nodules), most commonly on the shins.

• Redness on the palms of your hands may be caused by liver disease, pregnancy or an ghiandola tiroidea iperattiva (ipertiroidismo).

• A red rash may occasionally be due to an inflammatory condition called lupus eritematoso sistemico, especially if it is on the cheeks.

Red (erythema) and scaly skin rash

• Psoriasi. This is a condition where there is inflammation of the skin.

• Eczema. This is sometimes called dermatitis and also involves inflammation of the skin. It may be caused by an allergy and is then called atopic dermatitis/eczema. This may happen in response to some plants - eg, poison oak or ivy.

• Dermatite seborroica (in adults). This is a type of skin rash sometimes called seborrhoeic eczema. In babies it is known as cradle cap.

• Fungal (or 'yeast') skin infection, such as il piede d'atleta, groin infection (tinea cruris), ringworm, scalp ringworm or infection with candida.

• Pitiriasi rosea. This condition is described as 'self-limiting' and the rash will clear itself naturally.

• Pitiriasi versicolor. This is a rash which is caused by a yeast-like germ.

• Lupus erythematosus.

• Lichen planus. This condition mainly affects the skin and causes an itchy rash.

Macules

• Red macules may be due to a reaction to a medicine or a eruzione cutanea virale - come morbillo o rosolia - as well as other causes.

• A brown macule may be a mole but check with your doctor if a mole changes or you are concerned it might be a melanoma.

• A white macule may be due to a condition which causes pale patches of skin (called vitiligine) or a skin complaint with flaky discoloured areas (called pityriasis versicolor).

• If a macule is dark red or purple and does not fade when you put pressure on it then it is a purpura (see below) and you need to see a doctor urgently. This is because it could be a sign of meningite or blood infection (setticemia).

Papules

• Common causes of papules include cicatrici da acne, viral wart, seborrhoeic wart, mollusco contagioso, scabbia, morsi di insetto and skin tags.

• Other causes include psoriasi.

Purpura and petechiae

• These are dark red or purple and don't fade when you press them. You need to see a doctor urgently because there may be a serious cause that needs urgent treatment, such as meningococcal infection.

• However, common causes include injury to the skin or repeated coughing. More serious common causes include liver disease such as cirrosi.

• Less common causes include vasculitis (eg, Porpora di Henoch-Schönlein) or a low level of platelets in your blood (eg, porpora trombotica trombocitopenica).

Vasculite

© James Heilman, MD, CC BY-SA 3.0, via Wikimedia Commons

Nodules

• Common causes of a nodule include a cisti sebacea, lipoma, cancro della pelle, or a wart.

• Other causes include rheumatoid nodules (associated with artrite reumatoide) and Heberden's nodes (associated with osteoartrite).

Blisters

• Skin inflammation, including reactions to medicines, dermatite da contatto, eczema. Eczema on your legs may be caused by varicose veins (eczema varicoso).

• Diseases of your immune system - eg, bullous pemphigoid.

• Viral infections - eg, varicella, malattia mani-piedi-bocca.

• Skin infection: a germ (bacterial) infection with impetigo or viral infection with herpes simplex (herpes labiale o herpes genitale) or with herpes zoster (shingles).

• Rarer causes include pemfigo e pemfigoide.

Pustules

• Skin infection by a virus (eg, herpes labiale due to herpes simplex virus) or bacterial germs (impetigine).

• Inflammation - eg psoriasi.

• Pustular skin reaction to medicine you are taking.

• Pustules on your face may be acne or rosacea.

Ulcere

Ulcers may be due to venous leg ulcers, ulcere da pressione, diabetes skin ulcers o cancerous (malignant) skin ulcers.

This leaflet is a guide but if you have any concerns, you must telephone or see your GP, especially if:

• The rash doesn't quickly disappear.

• You feel unwell.

• The rash does not fade with pressure (the best way to test this is to press a glass gently against the rash to see if it fades).

• You are not sure what has caused the rash or have any other concerns.