The skin may reflect signs of systemic diseases, useful for diagnosis, or suffer from a complication of disease or its treatment. Here are links to pages about the dermatological manifestations of non-infectious internal diseases: immune, autoimmune diseases and rheumatic diseases; genetic, metabolic, endocrine and nutritional states; internal malignancy; haematological diseases; psychiatric states; and drug eruptions.
- Acrodermatitis enteropathica
- Acrodermatitis enteropathica-like conditions
- Acrodynia
- Acute febrile neutrophilic dermatosis
- Acute hepatic porphyrias
- Amyloidosis
- Angioedema
- Annular erythema
- Antiphospholipid syndrome
- Argyria
- Autoimmune disease
- Autoinflammatory syndromes
- Behçet disease
- Biotin–responsive dermatoses
- Blau syndrome
- Bloom syndrome
- Bowel bypass syndrome
- Calciphylaxis
- Carotenoderma
- Chilblains
- Chloracne
- Churg–Strauss syndrome
- CINCA
- CLOVES syndrome
- Compulsive skin picking
- Congenital adrenal hyperplasia
- Congenital erythropoeitic porphyria
- Connective tissue diseases
- Cornelia de Lange syndrome
- Costello syndrome
- Crohn disease
- Cronkhite–Canada syndrome
- Crouzon syndrome
- Cryoglobulinaemia
- Cushing syndrome
- Cutaneous markers of malignancy
- Cryopyrin-associated periodic syndromes
- Degos disease
- Dermatitis herpetiformis
- Dermatomyositis
- Diabetes
- Diabetic foot ulcers
- Down syndrome
- Drug eruptions
- Dysmorphophobia
- Ehler–Danlos syndrome
- Eosinophilic fasciitis
- Epstein–Barr virus-associated lymphoproliferative disorders
- Erythema multiforme
- Erythema nodosum
- Erythropoeitic protoporphyria
- Familial cold autoinflammatory syndrome
- Familial Mediterranean fever
- Flushing
- Focal dermal hypoplasia
- Genital Crohn disease
- Glucagonoma
- Gluten enteropathy in patients with dermatitis herpetiformis
- Goltz syndrome
- Gorlin syndrome
- Gout
- Graft versus host disease
- Granuloma annulare
- Haematological disease
- Haemochromatosis
- Heberden and Bouchard nodes
- Helicobacter pylori infection
- Histiocytic necrotising lymphadenitis
- Histiocytoses
- Hodgkin lymphoma
- Hypereosinophilic syndrome
- Hyperimmunoglobulinaemia D with periodic fever syndrome
- Hypogonadism in females
- Hypogonadism in males
- IgG4 disease
- Incontinentia pigmenti
- Iron deficiency
- Itch
- Job syndrome
- Juvenile systemic granulomatosis
- Kava dermopathy
- LEOPARD syndrome
- Lepra reactions in leprosy
- Livedo reticularis
- Lupus erythematosus
- Lyme disease
- Lynch syndrome
- Majeed syndrome
- Marfan syndrome
- Mastocytosis
- McCune–Albright syndrome
- Menopause
- Metabolic syndrome
- Mevalonic aciduria
- Monogenic autoinflammatory syndromes
- Morphoea
- Mucinoses
- Muckle–Wells syndrome
- Myxoma syndrome
- Necrobiosis lipoidica
- Necrolytic migratory erythema
- Neurotic excoriations
- NOMID
- Orofacial Crohn disease
- Orofacialdigital syndrome type 1
- Orofacial manifestations of inflammatory bowel disease
- Panniculitis
- PAPA syndrome
- Pellagra
- Periodic fever syndromes
- PFAPA syndrome
- Phaeochromocytoma
- Photosensitivity
- POEMS syndrome
- Polyarteritis nodosa
- Polymorphous eruption of pregnancy
- Porphyria cutanea tarda
- Pretibial myxoedema
- Primary cutaneous marginal-zone lymphoma
- Prolidase deficiency
- Protein-energy malnutrition
- Proteus syndrome
- Prurigo nodularis
- Pruritus
- Pseudoxanthoma elasticum
- Pyoderma gangrenosum
- Pyodermatitis–Pyostomatitis vegetans
- Reiter syndrome
- Reticular erythematous mucinosis
- Rheumatoid arthritis
- Rothmund–Thomson syndrome
- SAPHO syndrome
- Sarcoidosis
- Schnitzler syndrome
- Scleroderma (localised)
- Scleredema
- Scleromyxoedema
- Scurvy
- Sézary syndrome
- Sjögren syndrome
- Skin cancer in transplant recipients
- Skin signs of gastrointestinal disease
- Skin signs of neurological diseases
- Skin signs of rheumatic disease
- Stoma skin problems
- Sweet disease
- Systemic sclerosis
- Telogen effluvium
- Thyroid disease
- Toxic epidermal necrolysis
- Tuberous sclerosis
- Tumour necrosis factor receptor-associated periodic syndrome
- Turner syndrome
- Urticaria
- Variegate porphyria
- Vasculitis
- Vogt-Koyanagi-Harada syndrome
- Waldenström macroglobulinaema
- Granulomatosis with polyangiitis
- Wells syndrome
- Whipple disease
- Wilson disease
- Xanthomas
- Xeroderma pigmentosum