List differential diagnosis for contagious small bumps all over the body that itch

Answer 1

When evaluating contagious small bumps all over the body that are itchy, several differential diagnoses should be considered:

1. Scabies: Infestation by the Sarcoptes scabiei mite, leading to intense itching and a rash that can appear as small bumps or blisters.

2. Chickenpox (Varicella): A viral infection characterized by an itchy rash with small, fluid-filled blisters that eventually crust over.

3. Contact Dermatitis: A reaction to an allergen or irritant, which may become contagious if there is a secondary bacterial infection.

4. Impetigo: A bacterial skin infection, often presenting with red sores that can develop into itchy blisters and are contagious.

5. Molluscum contagiosum: A viral skin infection characterized by small, raised, flesh-colored bumps, which can be itchy.

6. Herpes Simplex Virus (HSV): Though typically localized, HSV can occasionally present with multiple vesicular lesions and itching, particularly during an outbreak.

7. Nummular Eczema: While not contagious, the bumps can resemble other contagious conditions and may become itchy, especially when scratched.

8. Lichen Planus: An inflammatory skin condition that can present with itchy, small bumps, and though not contagious, can be mistaken for other conditions.

9. Folliculitis: Infection of hair follicles, potentially caused by bacteria or fungi, leading to small, itchy bumps which can be contagious in some cases.

10. Fungal Infections (Tinea): Conditions like ringworm can present with itchy red bumps or patches and are contagious.

11. Viral Exanthems: Certain viral infections (like measles or rubella) can cause a rash with small bumps that may become itchy.

12. Allergic Reactions (Urticaria): Although not primarily contagious, severe allergic reactions can lead to widespread itching and bumps.

13. Pityriasis Rosea: A benign skin condition that presents with a rash that may cause itching, though not contagious.

It is vital to evaluate the overall clinical picture, history, and potential exposure to infections when considering these differential diagnoses, and consultation with a healthcare provider is recommended for accurate diagnosis and management.