IBD and Skin

Ulcerative colitis: Erythema nodosum, pyoderma gangrenosum and pyoderma vegetans (more common than CD)

Crohn's disease: PAN (but not with UC), oral cobblestone, perineal fissures and fistula

Hepatitis C skin manifestation

Vasculitis - mixed cryoglobulinemia
Porphyris cutaneous tarda
Lichen planus - erosive mucous LP
Cutaneous polyarteritis nodosa
Pyoderma gangrenosum
Pruritus
Others: Sjogren syndrome, urticaria, erythema multiforme, erythema nodosum, prurigo nodularis, disseminated superficial actinic porokeratosis, generalized GA, necrolytic acral erythema

Source: Rook's Dermatology 7th

Paraneoplastic pemphigus

Tumors associated with paraneoplastic pemphigus

Target antigens include desmoplakin (250kD), envoplakin (210kD), periplakin (190kD), bullous pemphigoid antigen-1 (230kD) and desmogleins 1 and 3.

Tay syndrome

Tay syndrome=Trichothiodystrophy

Photosensitivity
Icthyosis
Brittle hair
Intellectual impairment
Decreased fertility
Short stature

Elastosis Perforans Serpiginosa

Associated with PROMEDA

Pseudoexanthoma elasticum
Rothmund-Thomson
Osteogenesis imperfecta
Marfan's syndrome
Enles-Danlos syndrome
Down's syndrome (1/3 of the cases)
Acrogeria