Fever with rash differential diagnosis

Very itchy skin with localised rash - contact dermatitis, head lice, insect bites, lichen planus, lichen sclerosus, lichen simplex, pompholyx, venous eczema, Mildly itchy skin with localised rash - asteatotic eczema, psoriasis, seborrhoeic dermatitis, Very itchy skin with generalised rash - autoeczematisation, bullous pemphigoid, dermatitis herpetiformis, atopic dermatitis, discoid eczema, erythroderma, lichen planus, mycosis fungoides, neurodermatitis, nodular prurigo, scabies, Grover disease, urticaria, Mildly itchy skin with generalised rash - psoriasis, urticaria, xerotic eczema, Localised itchy skin without rash, Generalised itchy skin without rash - scabies, pregnancy, systemic disease Introduction An acute or chronic itchy rash is most often due to dermatitis/ eczema. Dermatitis can be primary, or secondary to scratching. Stages include: • Acute dermatitis: red, oozy, swollen skin • Subacute dermatitis: red, dry skin • Chronic dermatitis: skin coloured or dark, dry, thickened skin with prominent lines ( lichenification) • Infected dermatitis: painful, swollen, pustules, crusting. Stages of dermatitis • Dermatoscopic examination of hair shaft if scalp affected, possible burrows if hands affected • Swab for bacterial and culture if pustules, crusting • biopsy for histopathology, and if available, direct immunofluorescence • If the itch is generalised and no primary skin rash observed, check blood count, iron studies, renal, liver and thyroid function, chest X-ray. Gen...

The Differential Diagnosis This presentation fits within a diagnostic territory of an autoimmune disorder, a systemic inflammatory disorder, malignancy, and an infection. Let's further examine the differential diagnosis. Infection Supporting this diagnosis are the patient's fever, leukocytosis, high ESR and CRP, and adenopathy. When symmetric polyarthritis, rash, liver function test abnormalities, and hepatosplenomegaly are also present, the following need to be considered: • Bacterial endocarditis: The absence of a murmur and subacute bacterial endocarditis splinter hemorrhages argues against endocarditis, as does the presence of symmetric polyarthritis. Negative blood cultures would rule this out. • Hepatitis B and C: Both hepatitis B and C can be associated with polyarthritis, abnormal liver test results, rash, adenopathy, spleen and liver abnormalities, and anemia, but one would expect higher levels of AST and ALT in someone this sick. In addition, the leukocytosis would be uncommon. Hepatitis B and C serologic testing would help to rule out these conditions. • Disseminated gonococcemia: The patient's fever, joint inflammation, skin rash, leukocytosis, and elevated ESR would support this diagnosis, but the adenopathy, hepatosplenomegaly, symmetric polyarthritis, and transient nature of the skin rash would be uncommon. In addition, joint inflammation is usually migratory or monoarticular, while skin lesions are usually pustular or papular. Blood, genital, rectal, and th...

Tiny blood vessels, called capillaries, link the smallest parts of your arteries to the smallest parts of your veins. Petechiae form when capillaries bleed, leaking blood into the skin. The bleeding may be caused by: • Prolonged straining • Medicines • Medical conditions Prolonged straining Tiny spots on the face, neck and chest can be caused by straining for a long time from coughing, vomiting, giving birth or lifting weights. Medicines Petechiae may result from taking some types of medicine, including phenytoin (Cerebyx, Dilantin-125, others), penicillin and quinine (Qualaquin). Infectious diseases Petechiae may be caused by infection with a fungus, virus or bacteria. Examples of these types of infection include: • • • • Meningococcemia • • • • • Other medical conditions Petechiae may be caused by other medical conditions. Examples include: • • • • Scurvy (vitamin C deficiency) • • • Gottlieb M, et al. Dermatologic manifestations and complications of COVID-19. American Journal of Emergency Medicine. 2020: doi.org/10.1016/j.ajem.2020.06.011. • Bolognia JL, et al. Purpura and disorders of microvascular occlusion. In: Dermatology Essentials. 2nd ed. Elsevier; 2022. https://www.clinicalkey.com. Accessed Feb. 2, 2021. • Soutor C, et al., eds. The differential diagnosis of purpura. In: Clinical Dermatology: Diagnosis and Management of Common Disorders. 2nd ed. McGraw Hill; 2022. https://accessmedicine.mhmedical.com. Accessed Feb. 2, 2023. • Kelly AP, et al., eds. Bacterial inf...

Several conditions, including chickenpox, fifth disease, and roseola, can cause fever with a rash in a child. It is always best to call a doctor if a child has a fever with a rash. These viral illnesses can be unpleasant, but they usually go away on their own. Less commonly, however, a sudden rash with a fever might signal something more serious, such as a severe drug reaction. Parents or caregivers should always consult a doctor when a child has a fever with a rash, especially if the child is very ill or their symptoms get rapidly worse. Fifth disease A virus called parvovirus B19 causes a common childhood infection called fifth disease. Doctors may also call it “slapped cheek” disease because the rash often causes a red or darker patch on the cheek. The medical term is erythema infectiosum. The infection usually begins about Usually, the rash comes after the fever resolves, not at the same time. Fifth disease usually clears on its own. It can sometimes cause complications, such as Roseola A type of virus in the herpesvirus family Children with roseola usually get a fever and runny nose, and they may be The fever and rash rarely occur at the same time. Instead, the Roseola typically goes away on its own within a few days, and there is no specific treatment. Chickenpox A virus called varicella-zoster causes Chickenpox may begin with a fever, exhaustion, irritability, or a headache. The rash tends to appear within a day or two, presenting as many tiny, fluid filled blisters...

A viral exanthem rash is spots, bumps or blotches on your skin that accompany a viral infection. It may or may not be itchy. The rash can start anywhere on the body, often on your face or trunk, and then spread. It may be associated with other virus symptoms. There’s no cure for most viral infections, so treatment aims to make you more comfortable. Overview What is a viral exanthem rash? Exanthem is a medical term that describes a widespread rash. A viral exanthem rash accompanies a viral infection. It causes spots, bumps or blotches on your skin. You also might experience additional viral symptoms such as fever, fatigue and body aches. What is the difference between a viral and bacterial exanthem rash? An exanthem also can accompany a Who might get a viral exanthem rash? Anyone can get a viral exanthem rash, including children. How common is viral exanthem rash? These rashes are common, and so are many of the viruses that cause them. Symptoms and Causes What causes viral exanthem rash? A virus can cause a viral exanthem rash in one of three ways: • The rash is your body’s immune response to the virus. • Damage to your skin by the organism. • Reaction to a toxin the virus produces. Viruses that commonly cause exanthem rash include: • • • • (coxsackievirus A16). • • • Other viruses that may cause viral exanthem rash include: • Hepatitis. • • What are the symptoms of a viral exanthem rash? A viral exanthem rash causes spots, bumps or blotches on your skin. They can appear an...

General Presentation Children frequently present at the physician’s office or emergency room with a fever and rash. Although the differential diagnosis is very broad, adequate history and physical examination can help the clinician narrow down a list of more probable etiologies. It is important for physicians to be diligent, as the differential diagnosis can include contagious infections or life-threatening diseases. Even though there is a strong link between the presentation of fever and rash and infectious disease, it is important to keep in mind that other non-infectious diseases can also have similar presentations (e.g. drug reactions, cutaneous lupus erythematosus, inflammatory bowel disease). Presentation Features of the rash: – Characteristic of lesions – Distribution and progression – Timing of onset in relation to fever – Morphological changes (e.g. papules to vesicles) Common skin lesions: (see – Macule: nonpalpable, circumscribed, flat lesion (1 cm in diameter) – Pustule: pus-containing vesicle – Ulcer: depressed skin lesion with missing epidermis and upper layer of dermis Questions to Ask It is important to consider the following: – Age of patient – Season – Travel history – Geographic location – Exposures to insects, animals, other people who are ill – Medications – Immunization history – Other medical conditions – Immune status of patient – Was there a prodrome? (early symptoms that might indicate the start of disease) – When did the rash start? – Where did t...