RED RASHES ON THE SKIN? READ THIS INFORMATIVE DEEP-DIVE

A chronic skin disorder that presents as itchy, red dots, and rashes, Atopic dermatitis (AD) may recur from time to time. Having a personal or family history of asthma, allergic rhinitis, and atopic dermatitis are common factors involved in this skin condition. In infants, AD usually affects the face or cheeks, as well as the extensor surfaces of the arms and legs. In older children and in adults, lesions are most commonly seen in the flexural areas.

Also called discoid eczema, nummular eczema presents as coin-shaped, itchy, red lesions on the skin that may be oozing or crusted. This usually affects the extremities and may be triggered by a multitude of factors, such as changes in weather and other irritants and allergens.

Lichen simplex chronicus (LSC) and prurigo nodularis (PN) are skin conditions that are usually caused by persistent and recurring itching, scratching, or rubbing of the skin. They can be due to a systemic disease or by other possible causes, such as having a history of atopic dermatitis. Lesions of LSC and PN are known to have severe itching, triggering the patient to scratch, which causes the thickening of the lesions. LSC lesions are lichenified, scaly, and dry and may be erythematous or hyperpigmented in color. PN, on the other hand, appears as firm nodules.

Allergic contact dermatitis (ACD) and Irritant contact dermatitis (ICD) are skin diseases caused by a reaction to certain allergens that come in contact with the skin. Lesions may appear as itchy red dots or rashes, which can be accompanied by swelling, weeping lesions, or pain, depending on the severity of the disease.

Seborrheic dermatitis, more commonly known as dandruff, usually appears as red scaly patches on the scalp, face (eyebrows, ears, sides of nose), trunk, and back, especially on the oil-rich areas of the body. Some factors that may cause seborrheic dermatitis include:

1. A species of fungi called Malassezia
2. Other systemic diseases or decreased immune response
3. Increased oil production on the scalp or the skin
4. Stress and weather changes

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Psoriasis is a chronic skin disorder that is caused by a combination of genetic and environmental factors. Lesions often present as red dots that evolve into thick plaques that have white, scaly surfaces. Lesions usually appear on the scalp and on the extensor surfaces of the skin, such as the elbows and knees, but they can also appear anywhere in the body.

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A chronic skin condition, Pityriasis rubra pilaris appears as orange-red scaly plaques that can affect any part of the body but are usually found on the palms and soles. The presence of areas of unaffected skin called “nappes claires” is a diagnostic hallmark. There can also be some nail changes present.

Pityriasis rosea usually begins with the appearance of a solitary, red, round to oval-shaped, itchy “mother patch” on the trunk. After around two weeks, the mother patch is followed by the appearance of multiple lesions with the same morphology but in smaller sizes. Lesions also have some scaling on the periphery and can form a “Christmas tree” pattern on the upper chest and back. Aside from the trunk, the extremities can also be affected. The etiology is unknown but it is speculated to be viral in nature. Lesions usually disappear in 5-8 weeks.

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Lesions of lichen planus appear as red-violet, flat-topped, polygonal raised lesions commonly seen on the flexural arms, wrists, and legs. It is associated with fine, white scales called Wickham striae. The cause is unknown, but is postulated to be affected by infectious, immunologic, genetic, and metabolic causes.

Granuloma annulare is a benign skin disease that presents as annular or ring-like lesions that may be reddish, violaceous, or skin-colored. The most common sites affected include the hands, feet, wrists, ankles, and lower limbs.

Urticaria is a common skin condition that presents as red, itchy bumps or wheals (hives) on the skin. Most cases of urticaria are idiopathic, but some may be caused by infections, chronic autoimmune diseases, and other possible triggers. Lesions are not contagious and usually spontaneously disappear within 24 hours. It affects children, adolescents, and young adults but can still affect older age groups as well.

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Reactions to drug therapy commonly have skin manifestations and usually present as maculopapular, red, itchy rashes that may be accompanied by other systemic symptoms such as difficulty breathing and swelling of the eyes or lips. Those that present as cutaneous hypersensitivity reactions can also appear with blisters, pustules, or wheals. When hypersensitivity reactions are suspected, it is best to withdraw the offending agent and consult with your doctor as soon as possible.

Keratosis Pilaris (KP) presents as multiple skin-colored or reddish or light brown bumps most commonly seen on the lateral arms, thighs, or buttocks. Lesions of KP can be itchy or asymptomatic. This is a benign but chronic skin disorder and usually requires no treatment.

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Pemphigus vulgaris is an autoimmune blistering disease that presents as itchy or painful flaccid blisters that can evolve into scaly, crusted erosions on an erythematous base. These can appear anywhere in the body, as well as in mucous membranes.

Bullous Pemphigoid (BP) is another autoimmune blistering disorder that presents with itchy tense blisters on an erythematous base. BP is usually seen in the elderly and is commonly found on the flexural areas, lower abdomen, and thighs, but it can still appear anywhere in the body. These blisters or bullae are usually filled with serous fluid.

Dermatitis Herpetiformis appears as vesicles, bumps, or plaques that follow a herpetiform (herpes-like) pattern. DH lesions may be accompanied by itching, burning, or stinging sensation most commonly seen on the elbows, knees, buttocks, shoulders, and sacral areas. The scalp can also be affected. Lesions of DH tend to wax and wane. There is also associated gluten-sensitive enteropathy.

Cutaneous Lupus Erythematosus presents as the classic butterfly rash or malar rash, wherein the lesions appear on the malar eminences and over the bridge of the nose, with sparing of the nasolabial folds. More generalized forms appear as widespread maculopapular rashes on the extensor surfaces of the arms and hands, with sparing of the knuckles. Ultraviolet (UV) radiation is a usual trigger.

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Dermatomyositis is an autoimmune disease that presents as reddish to violaceous patches and plaques, which can be found on the scalp, trunk, posterior neck, upper back, and shoulders. These lesions are usually associated with muscle weakness.

Acne vulgaris is a common chronic inflammatory skin condition that affects the pilosebaceous unit. It is commonly seen in adolescents and presents with various skin lesions such as comedones (whiteheads and blackheads), papules, pustules, and even nodules and cysts in more severe cases. It can affect the face, back, chest, and shoulders.

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Rosacea is another chronic inflammatory skin condition that affects the central facial skin. It is characterized by facial flushing and can present with pimple-like lesions, spider veins or telangiectasias, and phymatous changes in the skin.

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Hidradenitis suppurative, also known as acne inversa, is a skin disorder that affects the hair follicles and is usually seen in the intertriginous and anogenital areas of the body such as the armpits, breasts, inner thighs, and groin area. Lesions present as tender and painful nodules or lumps that can progress to abscess-like lesions that drain purulent material.

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A skin condition seen in newborns, Erythema toxicum neonatorum presents as lesions that usually appear as blotchy, red patches with central vesicles or pustules. They can affect any part of the body, sparing the palms and soles. It is a benign condition and usually resolves spontaneously in 2-3 weeks.

Miliaria rubra, or “heat rash”, is a skin disorder affecting the eccrine (sweat) glands. Lesions appear as red papules and are usually caused by overheating.

Diaper dermatitis is a common skin disorder in infants. Most cases are due to underlying irritant contact dermatitis. Lesions present as red, moist, and sometimes scaly patches on the genital area and buttocks.

Basal cell carcinoma (BCC) is the most common skin cancer in humans. There are many types of BCC, but lesions usually appear as papules of nodules that can have ulcerations at the center, as well as telangiectasias and rolled borders. The head and neck are the most common areas affected.

Squamous cell carcinoma (SCC) is the second most common skin cancer in humans. There are many risk factors for SCC, but the most important one is high cumulative exposure to UV radiation. Lesions appear as red plaques or nodules that are slowly enlarging. Ulceration is also present. Lesions typically affect sun-exposed areas of the skin, especially the head, face, and neck region.

Infantile hemangiomas appear as red birthmarks in infant children. These lesions are benign vascular growths that usually disappear on their own.

Cutaneous vasculitis refers to the skin manifestations of inflamed blood vessels. Lesions usually appear as red spots, which are non-blanching and commonly affect the lower legs.

Kawasaki disease (KD) is a multisystem disorder that usually affects young children. This disease causes inflammation of the blood vessels. Skin lesions appear as red, itchy morbilliform rashes on the trunk and extremities, usually can be accompanied by fever, mucosal changes such as red lips or strawberry tongue, cervical lymphadenopathy, conjunctival injections, and swelling of the hands and feet.

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Pigmented Purpuric Dermatoses (PPD) are lesions that appear as reddish-brown patches or dots, associated with pigmentation and, sometimes, telangiectasias. They are often caused by leaky capillaries. The most affected areas are the lower legs.

Impetigo is a superficial bacterial skin infection presenting as red papules or fluid-filled vesicles that can rupture and form plaques with honey-colored crusts commonly found on the face or extremities, especially on the area of the nose or lips. Impetigo frequently affects young children.

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Folliculitis is another bacterial skin infection that specifically affects the hair follicles. Lesions appear as small, dome-shaped pustules with redness and some swelling around the hair follicle openings. Lesions can be itchy and are usually seen on hair-bearing areas of the body, such as the armpits, extremities, and buttocks.

Furuncles and carbuncles are deeper infections of the hair follicles. Furuncles, or boils, commonly appear as red, tender nodules which can affect the neck, face, armpits, buttocks, and any other hair-bearing areas of the body. When furuncles cluster together, they form a carbuncle.

Erythrasma is a superficial bacterial infection characterized by reddish-brown patches that are usually found on the intertriginous areas of the body. Diagnosis is usually aided by the presence of coral red fluorescence upon examination with a Wood’s lamp.

Cellulitis is a common bacterial infection affecting the deep dermis and subcutaneous tissue. Lesions are red and painful, can have accompanying edema or swelling, and are warm-to-touch. The lower extremities are most commonly affected.

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Erysipelas is commonly mistaken for cellulitis, as it appears as red plaques and can have accompanying edema. The differentiating factor is that lesions of erysipelas have sharply marginated and well-defined borders compared to the ill-defined borders of cellulitis. Most lesions affect the legs but can also appear on the face and upper extremities.

Tuberculosis (TB) does not only affect the lungs but can also affect the skin. Scrofuloderma and Lupus Vulgaris (LV) are some of the few kinds of cutaneous TB. Scrofuloderma lesions are commonly found in the submandibular, parotid, or supraclavicular area. LV lesions are usually seen on the head and neck.

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Leprosy, or Hansen’s Disease, is a mycobacterial infection that affects the skin, peripheral nerves, nasal mucosa, and eyes. Skin lesions of leprosy appear as red, hypopigmented, or hyperpigmented patches or plaques that have impaired or no sensation. There may also be nodules or lumps on the face, earlobes, or any part of the skin, as well as accompanying muscle weakness, nerve enlargement, or eye problems. Disfigurement of hands and feet is also possible.

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Superficial fungal infections can affect the hair, skin, and nails. Lesions usually appear as red itchy patches and plaques that tend to have advancing borders and scales.

Candidiasis is also a fungal infection that presents as beefy-red patches and plaques with satellite papules, usually affecting the intertriginous areas such as the armpits, groin folds, and inframammary area.

Measles, otherwise known as rubeola, is a viral infection that presents as small, nonpruritic, red dots or macules that start from the head or face and then spread downwards to the trunk and extremities. Lesions are usually preceded by fever, body weakness, colds, and cough. “Koplik’s spots” are also present on the oral mucosa. These are small, red macules that have a white speck on them.

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Rubella, also called German measles or 3-day measles, is a viral condition characterized by the presence of itchy pink to red dots that begin on the face and then increase to involve the neck, trunk, and extremities. Lesions can be associated with fever, muscle pains, sore throat, cough, and enlarged lymph nodes.

Erythema infectiosum, or Fifth disease, is a viral skin disease that commonly occurs in children. It presents with bright-red lesions on the malar surfaces, giving a “slapped-cheek” appearance on the face, followed by a lace-like eruption of lesions on the trunk and extremities. There may be accompanying symptoms such as headache, low-grade fever, body weakness, and joint pains.

Hand-Foot-Mouth disease is a viral skin condition that initially presents with low-grade fever and body weakness. The lesions can appear as bright pink dots and raised lesions on the palms and soles accompanied by oral lesions as well.

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Varicella, or chickenpox, is a highly contagious viral condition caused by the varicella zoster virus. Varicella lesions appear as vesicles or fluid-filled small blisters on a red base, usually starting on the face and scalp and spreading to the trunk. Mild fever, body weakness, and headache are some of the accompanying symptoms.

Herpes zoster or shingles is also caused by the varicella virus. Lesions also appear as fluid-filled small blisters that are clustered together, usually on one side of the body. Lesions are associated with pain.

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Secondary Syphilis is an infectious disease and is mainly sexually transmitted. There are 4 phases of the disease, and cutaneous manifestations are typically seen in the secondary stage. Lesions appear as red to copper-colored macules or papules that are sometimes scaly and usually not itchy. Lesions appear on the palms and soles but can usually affect the other parts of the body as well.

Lesions of cutaneous larva migrans appear as very itchy, serpiginous, and linear lesions usually caused by larval migration under the skin.

Scabies is a very common infestation seen in many different parts of the world. Transmission is due to the scabies mite being transferred either by direct contact or fomite transmission. Lesions usually appear as red dots and papules that are usually very itchy at night. It affects the armpits, wrists, abdomen, inguinal area, and other parts of the body. It is common for many members of the same household to exhibit the same lesions.

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Many arthropods or insects can bite or sting humans and cause skin reactions. Bedbug bites are one of the most common skin conditions due to arthropods. Lesions usually appear as a row of 3 or more red, itchy bites, called the “breakfast, lunch, and dinner” sign.