Heloma Durum (HD):
‘Hard corn’. Most common type. Localised thickening at areas of high pressure – considered a later stage of a callus. It is not clear what the forces/stress are that differentiates between a diffuse hyperkeratosis or a heloma durum developing – they are histologically similar. Could be assumed that the difference is due to the magnitude, direction, ‘concentration’ and duration of the mechanical forces.
Pressure/stresses hypertrophy of stratum corneum ‘conical’ mass developed if stress is more localised (called nucleus) displaces dermal tissues inflammation, oedema, pain
Occlusion of vessels from pressure of lesion localised tissue destruction ischaemic necrosis.
Hypergranulosis; acanthosis; inflammatory infiltrates; elongation and hypertrophy of epidermal rete pegs
Symptom of underlying bony or biomechanical pathology – often resistance provided by footwear or supporting surface or interdigital.
Appears as a circumscribed yellow hardened mass. Most are conical in shape. Removal of overlying hyperkeratosis shows the darker coloured nucleus. May have oedema and inflammation surrounding lesion with fibrosis beneath the lesion – may be associated with an adventitial bursa.
Usually found over an osseous prominence – most commonly on dorsal surface of digits, apices of digits, plantar surface of metatarsal heads, medial side of hallux, interdigitally, and in nail sulcus.
Occasionally they are deeper/thicker around the periphery with an atrophic centre.
Differential diagnosis – verruca pedis; foreign body; eccrine poroma; porokeratosis plantaris discreta.
Heloma durum and verrucae pedis are the two most common skin conditions and need to be differentiated:
Heloma durum: Verrucae pedis:
In areas of high pressure In any area
Skin lines pass through lesion Skin lines are displaced by lesion
No punctate bleeding on debridement Punctate bleeding on debridement
More painful on direct pressure More painful in lateral pressure/pinching
Usually adults Usually children and young adults
Insidious onset More rapid onset
No other lesions present May be other verrucae present
Heloma durum adjacent to proximal lateral aspect of nail of fifth toe – often difficult to see clear distinction between lesion and nail.
Debridement and enucleation of lesion almost always gives instant relief – may be followed by use of medicament (keratolytic, eg 15-30% salicylic acid) and/or accommodative padding Silicone gel pads (eg Silopos™) are being more commonly used.
Unless mechanical forces that caused lesion are removed, it will recur footwear advice, corrective or accommodative padding, silicone orthodigita, orthotic devices or surgery.
Complications of Helomas:
• necrosis of skin cells beneath hyperkeratotic skin due to continual pressure
• superficial ulcers usually heals well once lesion is debrided irrigate with sterile saline protective/accommodative padding
• deep ulcers and spread of infection to deeper tissues common in diabetic neuropathy more serious more aggressive management
• may infect ulcer debridement drainage irrigate with sterile saline protect with wound dressing and pressure relief padding
• if evidence of spreading/cellulitis antibiotic
• debridement of hyperkeratosis should be done under aseptic conditions to prevent possibility of infection