Differential Diagnosis for Rash with Itching and Burning

Single Most Likely Diagnosis

• Contact Dermatitis: This is a common condition that can cause a rash, itching, and burning, especially if the areas affected (eye, chest, groin, face, neck) have come into contact with an allergen or irritant. The distribution of the rash in areas that are more exposed or have thinner skin supports this diagnosis.

Other Likely Diagnoses

• Atopic Dermatitis (Eczema): Given the symptoms of itching and burning, atopic dermatitis is a plausible diagnosis, especially if the patient has a history of allergies or asthma. The rash can appear anywhere on the body but often affects the face, neck, and areas where the skin folds.
• Seborrheic Dermatitis: This condition causes scaly patches, red skin, and stubborn dandruff, often affecting oily areas of the body like the face, including the eyelids, and can spread to other areas like the chest and groin. Itching and burning sensations are common.
• Allergic Reaction: An allergic reaction to a substance (e.g., makeup, soap, detergent, or certain metals) could cause a rash, itching, and burning in the affected areas. The reaction could be localized or widespread, depending on the allergen and the individual's sensitivity.

Do Not Miss Diagnoses

• Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN): Although rare, these are life-threatening conditions usually triggered by medications or infections. They can start with symptoms similar to those described (rash, itching, burning), often involving the mucous membranes, and can rapidly progress to widespread skin necrosis and detachment. Early recognition is crucial for survival.
• Pemphigus Vulgaris: An autoimmune disease that causes blistering of the skin and mucous membranes. It can start with lesions in the mouth and then spread to the skin, potentially causing significant morbidity if not treated promptly.

Rare Diagnoses

• Pityriasis Rubra Pilaris (PRP): A rare skin disorder characterized by salmon-colored scaling patches, which can start on the face and spread to other parts of the body. Itching and burning can be present, although they are not the primary symptoms.
• Kawasaki Disease: Although more common in children, this condition can cause a rash, along with fever, swelling of the hands and feet, irritation and redness of the eyes, lips, throat, and tongue. It's a rare but important diagnosis to consider due to its potential to cause cardiac complications if not treated.

Each of these diagnoses has distinct features, but the clinical presentation can sometimes overlap, making a thorough medical history, physical examination, and possibly diagnostic tests necessary to determine the correct diagnosis.