Differential Diagnosis for Pediatric Rash on Dorsal Hands
Single Most Likely Diagnosis
- Callus or Friction Dermatitis: This is the most likely diagnosis given the location on the dorsal hands near knuckles, the description of a rough patch that is hyperpigmented, and the history of starting small and increasing in size. The lack of pruritus and bleeding also supports this diagnosis, as calluses are typically asymptomatic aside from the cosmetic appearance.
Other Likely Diagnoses
- Vitiligo: Although less common, vitiligo can present with hyperpigmented patches, but it typically starts with hypopigmentation. The location and description could fit, but the progression from small to larger might not be as typical for vitiligo.
- Lichen Planus: This condition can cause hyperpigmented, rough patches but usually involves the skin and mucous membranes and can be pruritic, which doesn't perfectly match the description provided.
- Keratosis Pilaris: This condition causes small, rough patches on the skin but is more commonly found on the arms, thighs, cheeks, and buttocks. It could potentially occur on the hands, but the specific location near the knuckles is less typical.
Do Not Miss Diagnoses
- Malignant Melanoma: Although extremely rare in children, any new or changing skin lesion, especially one that is pigmented and growing, must be considered for malignancy. The absence of other symptoms like bleeding does not rule out this diagnosis.
- Infectious Diseases (e.g., Mycobacterial Infections): Certain infections can cause skin lesions that might resemble the described rash. These are less common but critical to diagnose early due to their potential for serious morbidity.
Rare Diagnoses
- Dyshidrotic Eczema (Pompholyx): Typically presents with small vesicles on the palms or soles, which doesn't exactly match the description. However, it's a consideration in pediatric dermatology for hand lesions.
- Granuloma Annulare: This condition can cause ring-shaped lesions that might appear as rough, hyperpigmented patches. It's more common in children and young adults but doesn't typically start near the knuckles.
- Sarcoidosis: A systemic disease that can cause skin lesions, among other symptoms. Skin lesions in sarcoidosis can be varied and might fit the description, but the disease is rare in children and usually involves other systemic symptoms.