what is hyperkeratosis
hypertrophy of the stratum corneum resulting in excessive keratin formation
what can cause hyperkeratosis (7)
- anhidrosis
- bony deformities/prominences
- mechanical pressure from footwear/gait
- genetics
- smoking
- vitamin deficiency
- inflammatory skin disease
what are the characteristics of a physiological callus
- its a normal response to pressure/injury
- is the stimulus is removed, the stratum corneum usually recovers
what are the chatacteristics of a pathological callus
- if hyperkeratosis acumulates enough to cause pain, and persits despite removal of stimulus
- may lead to ulceration, particularly when nutrition of the tissues is impaired
how do dermal and epidermal cells react to mechanical stress
- they produce inflammatory cytokines, which result in incomplete differentiation of corneocytes
- in some genetic conditons (ichthyoses, keratiderma) mutatuions in keratin-encoding genes cause defects in keratin structure
what is the term used to describe proliferation of all epidermal layers, including the stratum corneum
acanthosis
what is parakeratosis
stratum corneum cells retain their nuclei
what risk factors are associated with hyperkeratosis in diabetic patients
higher risk of foot ulceration
how does hyperkeratosis commonly present in the foot (3)
- callus
- corns
- fissures e.g., plantar, calcaneal
how do corns differ from callus (4)
- focal papules of dry, rough skin
- common over bony prominences
- flesh coloured with a whiteish centre
- usually painful on direct pressure
where might corns/ callus be seen on the foot
high pressure areas such as:
* plantar MTPJ
* plantar calcaneus
* lateral 5th IPJ
* interdigital
where would a corn typically present in hallux limitus
2nd MTPJ
where is it common to see a corn in HAV
medial 1st MTPJ
where is it common to see a corn in the case of a tailor’s bunion
lateral 5th MTPJ
what are the features of intractable plantar hyperkeratosis (IPK) (5)
- very painful
- central fibrosis may be observed
- neurovascular elements
- more prevalent in smokers
- aka neurovascular corn
infectious pathologies that feature hyperkeratosis (2)
- verruca pedis/ warts
- fungal infection
non-infectious pathologies that feature hyperkeratosis (7)
- keratoderma
- ichthyoses
- psoriasis
- lichen planus
- eczema
- seborrheic keratosis
- actinic (solar) keratosis
objectives of hyperkeratosis management
- provide relief
- address extrinsic factors
- promote self-care
- consider intrinsic factors and non-conservative measures if required
management interventions (3)
- conservative
- surgical
- pharmaceutical
how to provide pressure relief (5)
- footwearmodification
- insole fabrication
- silicone devices
- padding materials
- casted devices
other than sharp debridement, what are alternative methods
caustics
