Itchy Rash

What is a Rash?

Rash is any abnormal change in skin color or texture. Medical terminology of rashes.

What is an Itch?

Itch is a sensation that provokes a desire to scratch. Itch diagnosis, prevention, and treatment.

Itchy vs Non-itchy Rash

Itch may help in diagnosis of rash. For example, bumps in keratosis pilaris usually don’t itch, in acne occasionally, in folliculitis often, and in allergy (bumpy hives) regularly. Severity of itch sometimes reflects severity of the disorder, for example, mild psoriasis doesn’t itch, but severe one does.

Here is a list of non-itchy rashes.

Itchy Rash

INFANTS and Itchy Rash

• Greasy yellowish scales on scalp (cradle cap) are result of overactive oil glands on infants scalp.
• Red patchy rash under diapers (diaper rash, napkin dermatitis) is due to fungal or bacterial infection, urine or feces irritation, atopic dermatistis, or psoriasis.
• Extensive skin scaling due to toxin released from bacterium Staphylococcus aureus occurs in Staphylococcal scalded skin syndrome (SSSS).

CHILDHOOD Diseases with Red Itchy SPOTS (Exanthema)

Exanthem (in Greek it means eruption) is widespread spotty rash, accompanied with fever, headache and malaise. It may be a result of skin damage by viruses or bacteria, their toxins or immune reactions.

• Chickenpox (Varicella zoster virus) appears with raised red spots (papules), vesicles, pustules that crust over and fall off with time. Rash is mainly on the face and trunk.
• Measles or morbilli (rubeolla virus) appear as red spots in the level of the skin (macules – up to 1 cm) on face, trunk, limbs, and raised whitish spots in mouth (Koplik’s spots). Cough is usually present.
• German measles (rubella virus) appear as pale red spots on the face and spreads all over the body.
• Roseola infantum or erythema subitum (herpes virus 6) appear as mild spotty rash on face and trunk.
• Fifth disease or erythema infectiosum (Parvovirus B19) is characterized by ’slapped cheeks’ rash, followed by spotty rash on trunk and limbs.
• Hand, foot and mouth disease (Coxsackie virus A16, or Enterovirus 71): small blisters appear on hands and feet, and painful ulcers appear in mouth.
• Pictures of chickenpox, measles, German measles, scarlet fever, fifth disease, and hand,foot and mouth disease.
• Hepatitis B, Epstein Barr virus(infectious mononucleosis), coxsackie viruses, echo viruses, and respiratory syncytial virus may appear as Gianotti Crosti syndrome with prominent red spots on limbs, trunk and finally on face. In Asymmetric Periflexural Exanthem of Childhood (APEC), a rash, supposedly of viral origin, appears in armpits or groin and spreads mainly over one side of the body. Pictures.
• Scarlet fever or scarlatina (Streptococcus group A or rarely Staphylococcus aureus) appear as tinny scarlet blotches (boiled lobster appearance) that coalesce and may cover the whole body in 24 hours. Sore throat and fever are usually present.
• Meningococcal disease is infection of inner brain membrane (meninge) by bacterium Neisseria memingitidis. Red dotty rash represent small bleedings that don’t disappear on pressure. Dots may merge to form bruise like rash. Neck stiffness, headache, nausea, fever and sensitivity to light are main symptoms.
• Kawasaki disease is inflammatory disease of uncertain (probably infectious) cause, resulting in red eyes, lips, tongue, hands and feet, widespread rash on the trunk, fever, malaise, and heart abnormalities.

CHILDHOOD Diseases With Red Scaly PATCHES

• Rash around the mouth in small children may be due to irritation from alkaline saliva.
• Rounded areas of hair loss and scaly skin appear in scalp ringworm (fungal infection with Tinea capitis).

Itchy Rashes in PREGNANCY

• PUPPP (Pruritic Urticarial Papules and Plaques of Pregnancy), also known as Polymorphous Eruption of Pregnancy or Polymorphic eruption is an itchy bumpy reddish rash appearing in the stretch marks of the abdomen in the last 3 months of pregnancy, and clears with delivery.

Itchy Red BUMPS

• Insect bites. Red, itchy, and often painful bump(s) appear on the site of bite of flyes, mosquitoes, ants, bees, wasps, spiders, scorpions, or snakes.
• Foreign object in the skin like a thorn causes bumpy red inflammation.
• Acne
  • Acne vulgaris – common acne (itch only occasionally) appear mostly in adolescence as red bumps with occasional white centers (whiteheads), and regularly with tinny black caps that block hair follicles (blackheads)
  • Acne rosacea
• Razor bumps appear as red bumps several hours after shaving or depilation; they represent ingrown hair
• Nonspecific skin rashes may be side effect of various drugs.
• Stye is a barley-sized red itchy bump due to bacterial infection of a hair follicle on the eyelid. Hordeolum is a pea-sized itchy red bump on the eyelid due to non-infectious inflammation of eyelid soft tissues. Itchy eyelids in detail.
• Miliaria (sweet rash) is a bumpy red rash, resulting from obstruction of sweat glands, appearing in hot weather, mostly on skin areas covered by clothes.
• Milia are small (1-2 mm) cysts on face formed from blocked hair follicles or sweat glands.
• Staphylococcal folliculitis appear as red bumps with white centers, just like acne, usually from staph infection of hair follicles. Click on link for pictures of staphylococcal and other types of folliculitis.
• Hot tub folliculitis are bumps with red haloes up to 1 cm wide, appearing under swim-suit, after using hot tubs contaminated with bacterium Pseudomonas aeruginosa
• Eosinophilic folliculitis appears as pale red bumps on face and neck, mostly in persons with immune deficiency (AIDS)
  
• Sea bather’s eruption are itchy red bumps appearing under swimming suit due to reaction on jellyfish larvae.
• Perioral dermatitis appears as scaly rash around mouth and eyes, almost exclusively in women
• Grover’s disease mostly appear in men over 50 who are unwell. Small pimple like red bumps appear on the chest or back.
• Bumpy hives are small pin-sized bumps with pinkish or reddish haloes around them. They usually appear in allergy due to physical stimuli like heat, cold, pressure, stress (cholinergic urticaria), or in allergy to food, medicines, cosmetics, sunscreens, hair dyes, jewelry, plants (poison ivy, poison oak), or sweat (prickly heat).
• Disseminate and recurrent infundibulofolliculitis (DRIF)
• Filariasis , strongyloidiasis
• Rocky mountain spotted fever is caused by rickettsiae, appear mainly in North America, and is characterized by groups of red blotches anywhere on the body. High fever is usually present.
• Dengue fever is flu-like viral illness, transmitted by mosquitoes from human to human. It appears with measles-like rash, high fever and muscular pains.

Itchy BOILS, NODULES and LUMPS

• Furuncle is a prominent, red, often painful bump (may be over 1 cm in size), usually appearing on the back of the neck, or limbs, as a result of staph infection. Carbuncleis collection of furuncles that merged together.
• In nodular prurigo several itchy red nodules with warty surface appear mainly on limbs. The cause is not known.
• Erythema nodosum appear as rounded slightly elevated red patches several cm in size, mainly on lower legs (also on thighs or forearms). They represent inflammation of under-skin fat, and may occur in tuberculosis, sarcoidosis, as side effect of drugs (sulphonamides, salycilates), contraceptive pills, or in pregnancy.
• In hidradenitis suppurativa, itchy lumps that may ooze fluid appear in armpits or in groin area.

Itchy Nevuses – Birthmarks

Nevus is a chronic delimited rash appearing as macule or mole.

Itchy Red PATCHES Without Scaling or Blisters

• Mild sunburn appears as itchy burning patch on the skin several hours after sun exposure.
• Hives (urticaria) , acute or chronic, physical urticaria (solar urticaria)
• Angioedema
• Extensive red discoloration of face, neck and upper chest appears within 30 minutes after scombroid fish poisoning.
• Pityriasis rosea (herpes virus 6 and 7). Pale red patch (’Herald patch’) few cm in size is followed by other small red scaly patches, mainly on trunk.
• Granuloma annulare mostly appear in children or young adults as a red ring with unaffected skin in the center. The cause is not known.
• Dermatomyositis is a muscular disease with a scaly reddish/violaceus rash, mainly on arms.
• Amyloidosis

Itchy SCALING Patches

• Fungal infections appear as scaly areas, mostly on feet (athlete’s foot – Tinea pedis), in groin (jock itch – Tinea cruris), on the body (ringworm of the body – Tinea corporis), or on the scalp (ringworm of the scalp – Tinea capitis). Details about itchy legs and itchy feet and toes.
• Lichen sclerosus is an itchy, shiny, scaly rash mostly appearing on women genitalia, but occasionally also on other parts of skin, and in children or men.
• Psoriasis is a genetic disorder, appearing as thick silvery scales on red skin surface with distinct borders, mainly on knees and elbows, or other parts of the body, including genital area or scalp. Itch appear only in severe cases.

Itchy Red PATCHES WITH SCALING, BLISTERS, and/or CRUSTS

• Severe sunburn Sunburn itch – prevention and treatment
• Actinic prurigo
• Chronic actinic dermatitis
• Photosensitivity is a condition where some drugs, or ointments react with UV rays from the sun, and causing strong reaction resembling severe sunburn.
• Dry skin (xerosis)
• Cold sore (herpes simplex virus) appear as a group of tinny translucent blisters on a reddened skin, usually on the lip border, or near the nose. The same rash may appear on genital mucosa.
• Shingles represent reactivation of herpes zoster (varicella) virus that remained dormant in nerve roots after chickenpox, and appears as a red rash resembling chickenpox over the course of a cranial nerve (on the face) or spinal nerve (on trunk or limbs), usually only on one side of the body.
• Poison ivy
• Severe cellulitis is under-skin infection, appearing as a bright red patch with large blisters, mainly on limbs, caused by bacterium Staphylococcus aureus or group A Streptococci.
• Tinea versicolor, also known as pityriasis versicolor
• A dermatophytide is an allergic rash caused by an inflammatory fungal infection at a distant site.
• An id reaction is an itchy rash with blisters that often occurs on the sides of fingers, but it can also be found on the chest or arms. It is actually caused by a fungal infection somewhere else on the body.
• Contact with some plants like nettle usually result in burning red patch with small translucent blisters. Contact with chrysanthenum may result in red patchy rash.
• Contact with some sea animals like jellyfish also result in a red patch.
• Eczema is a reddish patch with occasional scaling or blisters as a result of allergic contact dermatitis. It most often appears on hands.
• Atopic dermatitis
• Erythema multiforme appears on forearms and hands (also on knees or feet) as target-like rounded reddish rash with occasional blisters or crusts in the center. It occurs in some infections or as side effect of medications.
• Impetigo appears as red, scaly rash, often on face in children, but also in adults and on other parts of the body. The cause is infection with bacterium Staphylococcus aureus.
• Discoid eczema (nummular dermatitis) appears as coin-sized red rash anywhere on the skin.
• Paronychia is a red painful swelling of a nail base due to infection, usually with Staphylococcus aureus.
• In pemphigus, red patches with blisters and ulcers occupy extensive areas of skin and mouth mucosa. The cause is unknown. (Benign mucosal pemphigoid – itchy blisters ).
• Pompholyx are rough translucent blisters on hands or feet, often appearing in excessive palmar sweating.
• Scabies appear as red bumps, blisters and later scaling, mostly between fingers and toes, on inner sides of wrists, in skin folds, or anywhere on the body.
• Red rash with underskin canals appear in parasitic infestations with cutaneus larva migrans, tungiasis See pictures and check other causes of itchy feet and toes like acroangiodermatitis, sweaty sock syndrome, pitted keratolysis.
• Dermatitis herpetiformis
• Palmoplantar keratoderma is yellowish thickening of the skin on palms and/or soles, appearing in small children
• Paget disease appears as scally itchy discoloration of breast areola, and is almost always connected with breast cancer.

Itchy Rash With ULCERS

• Gravitational eczema (venous eczema, stasis eczema) appear on lower legs in persons with venous disease (varices, vasculitis) or thrombosis.
• Skin cancers: basal or squamous cell carcinoma, and rarely melanoma may appear as ulcers, our ulcerated masses on the skin.

Itchy Rash on SCALP, BEARD, ARMPITS or GROIN

• Dandruff appears as whitish skin flakes falling from the scalp, or other hairy skin areas.
• Seborrheic dermatitis appears as yellowish, greasy, flaky skin on the scalp, around ears or nose or in genital area.
• Head lice and pubic lice cause red bumps with intense itching on scalp (also on forehead, neck or shoulders) or groin skin.
• Epidermal or sebaceous cyst
• Tinea capitis (scalp ringworm) is fungal infection of the scalp, mostly in children.
• Barber’s itch (ringworm of the beard)
• Causes of itchy scalp in detail
• Tinea cruris (jock itch) is fungal infection of the inner thighs and groin
• Genital warts, plaques, and rashes due to sexualy transmitted diseases (STDs) may cause itch in the groin area. Read about rectal and anal itch.
• In hydradenitis suppurativa itchy lumps that may ooze fluid appear in armpits or in groin area.
• Fox-Fordyce disease is a rare disease resembling hidradenitis suppurariva but occurs mainly in young women (13-35 years of age). Sweat glands become clogged and small itchy bumps appear under the arm, or/and in the groin.
• Causes of itchy armpits in detail

Rash Around NAILS

• Fungal infection of nails – onychomycosis

Internal Diseases and Itchy Rash

• Liver disease with cholestasis, Wilson’s disease, Brucellosis of the liver, leptospirosis, trichinosis
• Kidney disease with uremia
• Crohn’s disease
• Celiac disease
• Systemic connective tissue diseases: Rheumatoid arhritis, Sjögren’s syndrome, systemic sclerosis
• Acanthosis nigricans, malignant are dry bumpy discolored skin (and mouth) lesions that often appear in abdominal malignancies.
• Chemochromatosis
• Lymphomatoid granulomatosis
• Androgen-, estrogen-, or drug-induced jaundice
• Hypersensitivity vasculitis, Polyarteritis nodosa, Polymyalgia rheumatica, Henoch Schonlein purpura
• Schistosomiasis
• SLE (rarely itches)

Further Reading:

List of Causes of Itchy Skin