Differential Diagnosis for Pain with Light Touch on a Particular Area of Skin
Single Most Likely Diagnosis
- Allodynia: This condition is characterized by pain resulting from a stimulus that does not normally provoke pain, such as light touch. It is often associated with neuropathic pain conditions, including postherpetic neuralgia, complex regional pain syndrome, and sometimes migraine. The presence of allodynia suggests an abnormality in the processing of sensory information by the nervous system.
Other Likely Diagnoses
- Neuropathic Pain: Conditions like diabetic neuropathy, trigeminal neuralgia, or peripheral neuropathy can cause pain in response to light touch due to nerve damage.
- Complex Regional Pain Syndrome (CRPS): A chronic pain condition that most often affects one limb after an injury or trauma, characterized by intense burning or aching pain, along with sensitivity to touch.
- Erythromelalgia: A disorder characterized by burning pain, heat, and redness in the hands and feet, which can be exacerbated by light touch or warmth.
Do Not Miss Diagnoses
- Shingles (Herpes Zoster): Although the rash is typically diagnostic, in some cases, especially before the rash appears (prodromal phase), the pain can be the only symptom, and it may be exacerbated by light touch.
- Meningitis: In rare cases, especially in patients with compromised immune systems, meningitis can present with severe sensitivity to touch or movement, among other symptoms like fever, headache, and stiff neck.
- Osteomyelitis or Deep Tissue Infections: While these conditions usually present with more systemic signs of infection, localized pain and tenderness to touch can be prominent features.
Rare Diagnoses
- Fabry Disease: A genetic disorder that can lead to neuropathic pain, including pain in response to light touch, due to the accumulation of a particular type of fat in the body's cells.
- Sickle Cell Disease: Certain crisis states in sickle cell disease can lead to intense pain episodes, which might include sensitivity to touch.
- Ehlers-Danlos Syndrome: A group of disorders that affect connective tissues supporting the skin, bones, blood vessels, and many other organs and tissues, which can lead to hypersensitivity and pain, including pain from light touch, in some cases.