Zaira Pellicer,^a Jesus Manuel Santiago,^b Alejandro Rodriguez,^b Vicent Alonso,^a Rosario Antón,^b and Marta Maia Bosca^b ,Ann Gastroenterol. 2012; 25(1): 21–26.

Almost one-third of patients with inflammatory bowel disease (IBD) develop skin lesions. Cutaneous disorders associated with IBD may be divided into 5 groups based on the nature of the association: specific manifestations (orofacial and metastatic IBD), reactive disorders (erythema nodosum, pyoderma gangrenosum, pyodermatitis-pyostomatitis vegetans, Sweet’s syndrome and cutaneous polyarteritis nodosa), miscellaneous (epidermolysis bullosa acquisita, bullous pemphigoid, linear IgA bullous disease, squamous cell carcinoma-Bowen’s disease, hidradenitis suppurativa, secondary amyloidosis and psoriasis), manifestations secondary to malnutrition and malabsorption (zinc, vitamins and iron deficiency), and manifestations secondary to drug therapy (salicylates, immunosupressors, biological agents, antibiotics and steroids). Treatment should be individualized and directed to treating the underlying IBD as well as the specific dermatologic condition. The aim of this review includes the description of clinical manifestations, course, work-up and, most importantly, management of these disorders, providing an assessment of the literature on the topic.

Management of cutaneous disorders related to inflammatory bowel disease (nih.gov)

Uwe Wollina, Orphanet Journal of Rare Diseases volume 2, Article number: 19 (2007)

Pyoderma gangrenosum (PG) is a rare noninfectious neutrophilic dermatosis. Clinically it starts with sterile pustules that rapidly progress and turn into painful ulcers of variable depth and size with undermined violaceous borders. The legs are most commonly affected but other parts of the skin and mucous membranes may also be involved. Course can be mild or malignant, chronic or relapsing with remarkable morbidity. In many cases PG is associated with an underlying disease, most commonly inflammatory bowel disease, rheumatic or haematological disease and malignancy. Diagnosis of PG is based on history of an underlying disease, typical clinical presentation, histopathology, and exclusion of other diseases that would lead to a similar appearance. The peak of incidence occurs between the ages of 20 to 50 years with women being more often affected than men. Aetiology has not been clearly determined yet.

Pyoderma gangrenosum – a review | Orphanet Journal of Rare Diseases | Full Text (biomedcentral.com)