Foot Pain (Podalgia)

INTRODUCTION

Serious disorders not to be missed The very important serious disorders to consider include:

• vascular disease—affecting small vessels

• diabetic neuropathy

• septic arthritis, osteomyelitis

• osteoid osteoma/other tumours (e.g. osteosarcoma)

• rheumatoid arthritis

• complex regional pain syndrome 1

• foreign bodies (e.g. needles, in children)

• ruptured tendons—Achilles, tibialis posterior

VASCULAR CAUSES

The main problem is ischaemic pain that occurs only in the foot. The commonest cause is atheroma.

Symptoms:

• claudication (rare in isolation)

• sensory disturbances, esp. numbness at rest or on walking

• rest pain—at night, interfering with sleep, precipitated by elevation, relieved by dependency

COMPLEX REGIONAL PAIN SYNDROME 1

Originally known as reflex sympathetic dystrophy, usually a sequel of trauma, usually lasts 2 yrs and recovery to normality usually follows.

Clinical features include sudden onset in middle-aged patients, pain worse at night, stiff joints and skin warm and red. X-rays that show patchy decalcification of bone are diagnostic.

Treatment includes reassurance, analgesics, mobility in preference to rest and physiotherapy.

OSTEOID OSTEOMA

Benign tumours of bone that typically occur in older children and adolescents. Nocturnal pain is a prominent symptom with pain relief by aspirin being a feature.

Diagnosis is dependent on clinical suspicion and then X-ray, which shows a small sclerotic lesion with a radiolucent centre. Treatment is by surgical excision.

OSTEOCHONDRITIS/ASEPTIC NECROSIS

Three important bones to keep in mind are:

• the calcaneum—Sever disease

• the navicular—Kohler disease

• the head of the second metatarsal—Freiberg disease

Sever disease is traction osteochondritis while the other disorders are a ‘crushing’ osteochondritis with avascular necrosis.

SKIN DISORDERS

Two conditions commonly seen in teenagers are pitted keratolysis and juvenile plantar dermatosis.

Pitted keratolysis This malodorous condition which has a pitted ‘honeycomb’ appearance is usually seen at 10–14 yrs. Known as ‘moccasin foot’, ‘stinky feet’ or ‘sneaker’s feet’, it is related to sweaty feet. Treatment includes keeping the feet dry, wearing all-leather shoes, cotton or woollen socks (not synthetics), charcoal inners and using clindamycin 1% lotion bd for 10 d to remove the responsible Corynebacterium organism.

Use a drying agent to decrease sweating. Preparations include formaldehyde soaks nocte or aluminium chloride 20% in alcohol solution (e.g. Driclor, Hidrosol, Neat Feat) applied nocte for 1 wk then 1–2 times/wk.

Juvenile plantar dermatosis ‘Sweaty sock dermatitis’ is a painful condition of weight-bearing areas of the feet. The affected skin is red, shiny, smooth and often cracked. It usually starts in school years and resolves in mid-teens and is rare in adults. The treatment is to change to leather or open shoes and to cotton socks. A simple emollient cream gives excellent ...