Organ transplants, skin changes

Basically, transplant recipients are threatened by 2 side effect scenarios: infections (60-90% of all organ transplanted patients are affected by bacterial, mycotic and viral skin infections (see below infections, opportunistic). After organ transplantation, severe or atypical clinical pictures are frequently observed, which are favoured by immunosuppression (reduced T-cell mediated immune response):

• • Bacterial infections (see below infections, opportunistic)
  • Viral infections ( CMV, HSV infections, HHV-6)
  • Mycotic infections (aspergillosis, candidosis)

Tumour diseases: The "Nonmelanoma Skin Cancer" is the most frequent new formation in organ transplants.

• • Kaposi sarcoma of the skin
  • Basal cell carcinoma
  • Carcinoma, cutaneous
  • Lymphoproliferative disease after transplantation (PTLD); see below lymphoma of the skin.

Bacterial infections

• Within the 1st month perioperative or nosocomial infections predominate. In this phase of recurrent infections, antibiotic-resistant bacterial strains come to the fore: vancomycin-resistant enterococci; methicillin-resistant staphylococci (MRSA).
• Individual case reports of Staphylococcal Scalded Skin Syndrome or Toxic Epidermal Necrolysis (TEN) in liver transplantation are available.
• The spectrum of bacterial infections ranges from impetigo contagiosa to follicular pyoderma (e.g. purulent folliculitis or boils), ecthymas and erythrasma.
• Erysipelas is usually not observed until several years after transplantation. It is not uncommon for severe forms to be observed with haemorrhagic, abscessing or necrotizing - gangrenous processes (e.g. necrotizing fasciitis).
• Atypical skin infections caused by Escherichia coli (e.g. folliculitis, gram-negative) are also observed in organ transplant patients.
• Nocardiosis: Within a period of 3 years up to 4% of organ recipients developed infections caused by N. asteroides. They manifest themselves in the skin through subcutaneous abscesses and nodules.

Atypical mycobacterioses are rather rare. Clinically there are phlegmonous processes, ulcers, abscessed nodules, granuloma formation.

• After 6 months and later; gradual reduction of immunosuppression, gradual normalization of immunological response with "normal course" of infections.

Viral infections

• 50% of all bone marrow transplants and 30% of all organ transplants show a reactivation of HHV 6 and these infections remain clinically mostly inapparent. Occasionally, uncharacteristic exanthema is observed.
• 30-40% of all organ transplants show reactivation of herpes simplex virus infections within the first 3 weeks. Clinical manifestation are extensive or necrotizing orolabial or genitoanal herpes simplex diseases, dissemination of HSV infections with pneumonia, hepatitis or encephalitis with potentially fatal course is possible.
• In the first 6 months (later than HSV and CMV), zoster infections are observed in 10-30% of organ transplanted patients. The infections are often complicated by bleeding and/or extensive necrosis or generalisation ( zoster generalisatus). Zoster recurrences unusual in immunocompetent patients are possible in organ transplant patients. Systemic spread of zoster infection can lead to life-threatening complications with pneumonia, vasculitis, intravascular coagulation, CNS involvement, hepatitis and pancreatitis.
• Polyomavirus infections are about 20 times more common after organ transplantation than cytomegalovirus (CMV) infections. Merkel cell carcinomas are known as skin manifestation by polyomaviruses.
• Cytomegalovirus (CMV) infections after organ transplants can cause mononucleosis-like symptoms with fever, leukopenia, morbilliform exanthema or vasculitis. Large genitoanal ulcers, but also ulcers on the tongue are characteristic of CMV infection in immunocompromised patients. Other important viral skin manifestations are:
• HPV infections (see below papilloma viruses, human) e.g. extensive verrucae vulgaris or condylomata acuminata.
• Molluscum contagiosum viruses: see below Molluscum contagiosum.
• Epstein-Barr virus infections: post-transplant lymphoproliferative disorder (PTLD); mostly non-Hodgkin lymphomas (primary cutaneous lymphomas - especially T-cell lymphomas - have been described in individual cases).
• HHV-8 infections: S. and Kaposi's sarcoma.

Dermatomycoses

• The most important transplant-associated fungal infections of the skin are Candida infections, dermatophyte infections (> 60% of kidney transplanted patients suffer from tinea ) and infections caused by Malassezia furfur. Remarkable is the high incidence of pityriasis versicolor (<35%), especially in kidney transplanted patients.
• Mucocutaneous candida infections ( Candida albicans) are usually found in the 1st year after transplantation. They are observed in about 10% of transplanted patients.
• Systemic mycoses: In about 10% of immunocompromised patients secondary hematogenically induced dermal infection with Candida and Aspergillus species (disseminated aspergillosis).
• Rare mycoses caused by mucor species (see below mucor mycoses), pheohyphomycetes (see below pheohyphomycosis), alternaria (see below alternariosis, cutaneous) or by Wangiella dermatitides are observed.
• Organ transplant patients have a significantly increased risk of developing Cryptococcus neoformans infection.

Malignant diseases

• Nonmelanoma Skin Cancer: Organ transplant patients have an approximately 250 times higher risk of developing carcinoma in situ of the actinic keratosis type compared to the normal population, and an approximately 100 times higher risk of developing invasive squamous cell carcinoma. The ratio of basal cell carcinoma to invasive squamous cell carcinoma is 3:1 for the normal population and 1:4 for organ transplant patients. The type and manner of drug-based immunosuppression has a decisive influence on the incidence rate. The risk increases with multiple combinations. Azathioprine was shown in one study to have the highest risk (8.8 times), followed by corticosteroids (3.9 times). UV radiation and light skin type have a cumulative effect.

Other inflammatory diseases

• Psoriasis vulgaris: No valid data exist on this. However, experience shows that long-term immunosuppressive therapy tends to worsen the disease (see case report on psoriasis vulgaris).

1. Diepgen TL (2010) Skin cancer risk with immunosuppression. Dermatology at work and in the environment. 58: 178-184
2. Ulrich C et al (2008) Skin infections in organ transplant patients. SDDG 6: 98-105