| Inbound Relationships | Type | Active | Source | Characteristic | Refinability | Group | 
| Diffuse palmoplantar keratoderma of Thost-Unna | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Enucleation of corn | Direct morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Inflammatory hyperkeratotic dermatosis, chronic | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Acrokerato-elastoidosis | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Acrokerato-elastoidosis | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Palmar hyperkeratosis of yaws | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Acquired plantar keratoderma | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Palmar callosity | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Enucleation of corn | Direct morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Removal of corn sinus | Direct morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Keratoderma areata | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Palmoplantar hyperkeratosis sclerodactyly syndrome | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Keratoderma with mental retardation and spastic paraplegia | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Mutilating keratoderma | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Autosomal dominant mutilating keratoderma | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Congenital palmoplantar and perioral keratoderma of Olmsted | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Congenital keratoderma | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Keratoderma with pachyonychia congenita | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Keratoderma punctata | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Leukoplakia of penis | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 3 | 
| Epidermolytic palmoplantar keratoderma of Vorner | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Excessive keratinized residual ridge mucosa | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Keratoderma | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Minimal keratinized residual ridge mucosa | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Hereditary diffuse palmoplantar keratoderma | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Hereditary palmoplantar keratoderma | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Focal hyperkeratosis | Is a | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier |  | 
| Punctate palmoplantar keratoderma | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Palmoplantar keratoderma | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Keratoderma with deafness | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Palmoplantar hyperkeratosis-hyperpigmentation syndrome of Cantu | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Palmar hyperkeratosis of yaws | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Plantar hyperkeratosis of yaws | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Hyperkeratosis of yaws | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Palmar callosity | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 3 | 
| Guttate hypopigmentation and punctate palmoplantar keratoderma with or without ectopic calcification | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 3 | 
| Gonococcal keratosis | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Keratosis palmoplantaris and arrhythmogenic cardiomyopathy syndrome | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 6 | 
| Syndromic recessive X-linked ichthyosis | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier |  | 
| Keratoderma hereditarium mutilans with ichthyosis syndrome | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Punctate palmoplantar keratoderma type 1 | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Hereditary palmoplantar keratoderma Gamborg Nielsen type | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Autosomal dominant diffuse palmoplantar keratoderma Norrbotten type | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Autosomal recessive palmoplantar keratoderma and congenital alopecia syndrome | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 7 | 
| Self-healing collodion baby | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 5 | 
| Acral self-healing collodion baby | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 5 | 
| Autosomal dominant palmoplantar keratoderma and congenital alopecia | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 7 | 
| Wooly hair and palmoplantar keratoderma with dilated cardiomyopathy syndrome | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 8 | 
| Haim Munk syndrome | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 5 | 
| Diffuse palmoplantar keratoderma and acrocyanosis syndrome | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 3 | 
| Intellectual disability, enteropathy, deafness, peripheral neuropathy, ichthyosis, keratoderma syndrome | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 5 | 
| Cerebral dysgenesis, neuropathy, ichthyosis, palmoplantar keratoderma syndrome | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 5 | 
| Palmoplantar keratoderma Nagashima type | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 3 | 
| Spastic paraplegia, intellectual disability, palmoplantar hyperkeratosis syndrome | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 6 | 
| Palmoplantar keratoderma with deafness syndrome | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 7 | 
| Palmoplantar keratoderma, 46,XX sex reversal, predisposition to squamous cell carcinoma syndrome | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 6 | 
| Palmoplantar keratoderma with clinodactyly syndrome | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 6 | 
| Callosity caused by biting and/or chewing | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Callosity | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Callosity on toe | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Callosity between toes | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Callosity under metatarsal head | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Senile keratoma | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Apical callus | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Foot callus | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Prayer nodule | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Diffuse callus | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Pinch callus | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Callosity on hand | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Callosity resulting from occupation | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Callosity due to habit tic | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Callosity caused by prosthesis and/or appliance | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Plantar callosity | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Pretalar callosity | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Familial painful callosities | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Callus of heel | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Multiple sclerosis, ichthyosis, factor VIII deficiency syndrome | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 7 | 
| Callosity caused by biting and/or chewing | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Onychophosis | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Hyperkeratosis of mucous membrane of mouth due to and following traumatic injury | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 6 | 
| Arsenical keratosis | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Wooly hair with palmoplantar keratoderma syndrome | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Punctate palmoplantar keratoderma type 2 | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Hypotrichosis, osteolysis, periodontitis, palmoplantar keratoderma syndrome | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Keratosis linearis, ichthyosis congenita, sclerosing keratoderma syndrome | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Keratosis linearis, ichthyosis congenita, sclerosing keratoderma syndrome | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Curly hair, acral keratoderma, caries syndrome | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 3 | 
| Ichthyosis, alopecia, eclabion, ectropion, intellectual disability syndrome | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 4 | 
| Curly hair, acral keratoderma, caries syndrome | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Nail and tooth abnormalities, marginal palmoplantar keratoderma, oral hyperpigmentation syndrome | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Hereditary benign acanthosis nigricans | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 3 | 
| Acanthosis nigricans due to type 2 diabetes mellitus | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Hereditary benign acanthosis nigricans with insulin resistance | Associated morphology | False | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 3 | 
| Acanthosis palmaris | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Hereditary benign acanthosis nigricans | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Drug-induced acanthosis nigricans | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Acquired acanthosis nigricans | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Benign acanthosis nigricans | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Hereditary benign acanthosis nigricans with insulin resistance | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 1 | 
| Malignant acanthosis nigricans | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 2 | 
| Leukoencephalopathy, palmoplantar keratoderma syndrome | Associated morphology | True | Hyperkeratosis | Inferred relationship | Existential restriction modifier | 3 |