Using chimeric human epidermal reconstructs, we previously demonstrated that epidermal pigmentation is dependent upon the phototype of melanocytes. We report here several lines of experimental evidence for dermal modulation of human epidermal pigmentation. First, phototype II-III epidermal reconstructs grafted on the back of immunotolerant Swiss nu/nu mice developed a patchy pigmentation dependent on the presence of colonizing human or mouse fibroblasts. Similarly, human white Caucasoid split-thickness skin xenografted on the same mouse strain became black within 3 months and histochemistry revealed a phototype VI pattern of melanin distribution. In vitro, human fibroblasts colonizing human dead de-epidermized dermis (DDD) induced a decrease in epidermal pigmentation whereas mouse (Swiss nu/nu) fibroblasts increased epidermal pigmentation. Conditioned medium from mice (Swiss nu/nu) fibroblasts also increased pigmentation whereas conditioned medium from human fibroblasts had no significant effect. Lastly, epidermal reconstructs made with normal or vitiligo keratinocytes and/or normal or vitiligo melanocytes from the same donor grown on DDD originating from several donors of the same clinical phototype did not pigment similarly and no specific dermal influence was noted for vitiligo. Thus, fibroblast secretion and acellular dermal connective tissue itself significantly influence melanocyte proliferation and melanin distribution/degradation. Our study suggests that murine fibroblasts are more potent than human fibroblasts in secreting soluble factors which can act directly on pigmentation, such as SCF, or activate keratinocytes to produce basement membrane proteins or melanogenic factors.

Therapeutic, IV.

No abstract

Reverse dorsal digital and metacarpal flaps use the dorsal skin of the digital or metacarpal areas, and they are based on the arterial branches anastomosing the volar and dorsal arterial networks of the fingers. These flaps are transposed as reverse island flaps. Dissection of the flap is easy, fast, and preserves the collateral nerve and artery to the fingertip. A series of 27 flaps is reviewed, with more than 6 months of follow-up. Skin defects in all patients were located over or beyond the proximal interphalangeal joint as far as the fingertip and were combined with bone, joint, or tendon exposure. The flaps we used were reliable, and a joint or extensor tendon reconstruction could be performed at the same time. Patients were discharged the day after surgery and allowed to mobilize the finger early. No flap necrosis was observed, and donor site morbidity was minimal; primary closure or a skin graft was used in all patients. These flaps combine the advantages of an extended skin paddle and a versatile pivot point on the phalanx, and they allow coverage of wide and distal defects. When conventional local flaps are inadequate, this fast and simple procedure should be considered for its reliability and low associated morbidity.

We report our experience with the use of Integra® for the management of severe traumatic wounds of the hand. Fifteen patients were treated with follow-up ranging from 10 to 37 months. Wounds were associated with an osseous and/or joint and/or tendon exposure. Following Integra® placement, patients were managed with dressings and subsequent split-thickness skin grafting an average of 26 days later. Integra® was successful in achieving durable, functional and aesthetic definitive coverage in 13 of 15 applications while allowing a satisfying pollicidigital prehension. Regarding our clinical experience, Integra® is an effective technique to deal with severe wounds of the hand with exposed tendon and/or bone and/or joint, even in the absence of paratenon or periosteum. This can potentially lessen the need for local rotational or free flap coverage and should be taken into consideration as a viable alternative in traumatic reconstruction of the hand.

KPIF was introduced as a single-stage alternative reconstructive option for partial thickness alar defects, completing author's experience with this flap into such a challenging and aesthetically critical anatomic area.

Calcaneal osteomyelitis is characterized by frequent relapse with delayed wound healing. Clinicians should take into account the impact of older age, as well as co-morbidities such as diabetes mellitus or the presence of neuropathy, during the routine management of patients with this difficult-to-treat bone infection.

In this study, the laser at 924/975 nm combined with curettage was determined to be the optimal treatment option of those tested for axillary hyperhidrosis. This treatment was safe, with few side effects and improvement that persisted to one year follow-up.