Histopathological diagnosis of graft-versus-host disease of the skin: an interobserver comparison.

BACKGROUND: Histopathology is an important tool in diagnosing cutaneous graft-versus-host disease (GvHD). Minimum diagnostic criteria for active chronic GvHD have recently been defined. However, they are not specific and their interpretation is dependent on observer judgement. AIMS OF THE STUDY: i) to explore interobserver variability in the interpretation of histopathological changes in GvHD, and ii) to analyse the impact of detailed clinical data on histopathological diagnosis of GvHD. METHODS: Histopathological slides from 15 skin biopsies of GvHD and from dermatoses with histopathologically similar appearance were sent in two phases to four dermatopathologists experienced in cutaneous GvHD in France, Germany, Italy and Switzerland (first round of 'blind' review followed by a second round with complete clinical information provided). RESULTS: Interface dermatitis, especially vacuolar alteration, was the most inconsistently evaluated, particularly in cases with minor alterations. Interestingly, for vacuolar alteration and apoptotic keratinocytes, interobserver variability was lower in the adnexal epithelia than in the interfollicular epidermis. Complete clinical information resulted in increased diagnostic confidence and greater concordance on the final diagnosis, rising from 53% (first round, k = 0.345, fair agreement) to 80% (second round, k = 0.529, moderate agreement). The percentage of correct diagnoses increased from 33.3% to 80%. CONCLUSION: For the diagnosis of GvHD, histopathological analysis is of importance, but, for correct diagnosis, the correlation of pathological findings with clinical results is crucial. In cases of minor alteration, histopathologists should focus on the interpretation of vacuolar changes and apoptotic keratinocytes, possibly on the adnexal epithelia.

Partial reconstitution of cutaneous microvessels in long-term survivors after allogeneic bone marrow transplantation.

BACKGROUND: Graft-versus-host disease (GVHD) is a major complication after allogeneic hematopoietic stem cell transplantation (HSCT) and skin is involved in acute and chronic disease. Immune-mediated vessel attack and subsequent microvessel loss have been observed in skin of patients with chronic GVHD. OBJECTIVES: To test whether long-term survivors (LTS) after allogeneic HSCT without cutaneous GVHD show signs of persistent vascular remodeling. METHODS: Microvessels in skin biopsies were investigated in a cohort of 32 LTS with a median follow-up of 17 years (range 11-26). Five were currently classified as having chronic GVHD other than skin involvement. RESULTS: LTS showed no significant difference in median microvessel density and relative vessel size distribution pattern compared to healthy controls. Past experience of GVHD and current status of chronic GVHD other than skin involvement had no impact on vessel density. In contrast, recipients with chronic cutaneous GVHD of sclerotic type and patients with lichen sclerosus have significant microvessel loss in the upper dermis. CONCLUSION: The complex therapy of allogeneic HSCT had no sustained effect on the microvascular architecture of LTS when clinicopathological evidence of cutaneous GVHD is absent. Microvascular remodeling as observed during chronic GVHD recovers completely after resolution of chronic cutaneous GVHD.

Acute generalized exanthematous pustulosis induced by the antifungal terbinafine: case report and review of the literature.

Cutaneous drug reactions occur with a frequency of 1-8% and can be higher for certain classes of drugs. They can range from mild morbilliform eruptions to more severe forms such as drug-hypersensitivity syndrome, toxic epidermal necrolysis or anaphylaxis. Acute generalized exanthematous pustulosis (AGEP) is considered to be a clinical reaction pattern, which is induced in over 90% of the cases by systemic drugs. It is a rare presentation of an adverse drug reaction most frequently triggered by anti-infectious drugs. A high proportion of these cases have been attributed to aminopenicillins and macrolides. We report a terbinafine-induced AGEP in a 68-year-old male confirmed by lymphocyte stimulation in vitro, and review the published cases induced by antimycotic drugs with special emphasis on terbinafine-triggered cases.