Rote memorize this info. Then answer the questions at the end. No pain no gain.
Dupuytren contracture
- Thickening of the palmar fascia of the hand.
- Presents as hard palmar nodule(s) with varying severity of finger flexion.
- Risk factors are alcoholism, diabetes, epilepsy, Norwegian descent.
- Diagnosis is clinical (i.e., Hx and P/E), but often associated with positive “tabletop test” → patient cannot place palm flat on the table.
- Treatment is with fasciotomy.
Ganglion cyst
- Fluid-filling swelling overlying a joint or tendon sheath.
- Arises from herniation of dense connective tissue from tendon sheaths.
- Most common site is dorsal aspect of the wrist adjacent the extensor carpi radialis brevis tendon.
- Treatment is either observation or needle drainage. Recurrence is common.
- For USMLE, this is a HY spot-diagnosis.
Mucous cyst (mucocele; digital myxoid cyst)
- Fluid-filled sac located at the DIP.
- Has an underlying stalk that connects to the joint.
- Associated with osteoarthritis; thought to be caused by tissue matrix breakdown.
- Treatment is surgical excision.
Verruca vulgaris (common wart)
- Usually caused by HPV 1, 2, 4.
- Not caused by strains associated with genital warts (6, 11) or SCC (6, 18).
- Treat with podophyllum resin or salicylic acid; can also do cyrotherapy or electrodissection.
Glomus tumor
- Tumor of the glomus body (specialized dermal smooth muscle cells) in the nail bed.
- Glomus bodies are numerous in fingers and toes and are involved in thermoregulation.
- “Strange” diagnosis that has a way of showing up now and again in USMLE assessment.
Subungual melanoma
- Melanoma occurring under the fingernail.
- Important spot-diagnosis for USMLE.
- Do not confuse this with subungual fibroma, which is associated with tuberous sclerosis (don’t need to know the image for this, just that it’s associated with TSC).
Felon
- Abscess of the tip of the finger.
- Usually Staph aureus.
- Treat with incision and drainage (I&D). Give oral dicloxacillin or cephalexin after the I&D for uncomplicated cases.
Herpetic whitlow
- HSV1 or 2 infection of the finger.
- Seen classically in dental professionals.
- Important spot-diagnosis for USMLE.
- Give oral acyclovir to treat.
Mycobacterium marinum
- Non-tuberculous mycobacterium causing red cutaneous ulcers and blisters.
- Associated with aquarium workers and visits to waterparks.
- “Strange” diagnosis that is HY on the USMLE.
- Students tend to get this wrong because they think water = Pseudomonas, but the latter is more hot tub folliculitis and otitis externa (swimmer’s ear); it also tends to cause blue-green skin discoloration due to pyocyanin. In contrast, M. marinum causes red skin lesions.
Bouchard and Heberden nodes
- Bouchard node = bony swelling of PIP joint.
- Heberden node = bony swelling of DIP joint.
- B comes before H in the alphabet the same way proximal comes before distal (Bouchard – Proximal IP joint; Heberden – Distal IP joint).
- Both seen in osteoarthritis (OA).
- Rheumatoid arthritis (RA) does not affect the DIP joints. If you get a hand x-ray that shows DIP swellings, you know right away it’s not rheumatoid arthritis (not always OA, but certainly not RA).
- Do not confuse these with Boutonniere and swan neck deformities seen in rheumatoid arthritis.
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