Reactive perforating collagenosis: light, ultrastructural and immunohistological studies

Dermoscopy Features of Acquired Perforating Dermatosis Among 39 Patients

In this report, we concluded there are four dermoscopic features of APD including a yellow-brown homogeneous structureless area in the center of the lesion, dotted and linear vessels distribution radially and a dam shape uplift at the periphery, as well as a white irregular ring surrounding the lesion. There are three features, including the yellow-brown homogeneous structureless area in the center of the lesion, the dotted and linear vessels distribution radially and the white irregular ring surrounding the lesion were correspond to the report of Emma Ormerod et al.These features are also similar to those previously discribed in three separated reports of seven cases with APD. In our report, we found a new dermoscopic features: the dam shape uplift at the periphery. These finding may be contributed to improve the rate of clinical diagnosis of APD.

Acquired reactive perforating collagenosis: current status

Acquired reactive perforating collagenosis is a unique perforating dermatosis, characterized clinically by umbilicated hyperkeratotic papules or nodules and histologically by a focal hyperkeratosis in direct contact with transepidermal perforating dermal collagen. Several inflammatory or malignant systemic diseases may coexist with acquired reactive perforating collagenosis. The possible biochemical or immunological mechanisms of the systemic diseases, potentially responsible for the development and appearance of acquired reactive perforating collagenosis, are still under investigation. Several topical treatments, ultraviolet B phototherapy and allopurinol p.o. administration may be effective.

Familial reactive perforating collagenosis

Background:

Reactive perforating collagenosis (RPC) is one of the rare forms of transepidermal elimination in which genetically altered collagen is extruded from the epidermis. This disease usually starts in early childhood as asymptomatic umbilicated papules on extremities, and the lesions become more conspicuous with age.

Aims:

The objective of our study was to determine the clinico-pathological features of RPC and the response to various treatment modalities.

Methods:

Ten patients of RPC, belonging to five different families, were studied clinically. Various laboratory investigations were carried out and diagnosis was made by histopathology of the lesions. Patients were given various topical and oral treatments.

Results:

RPC is familial in most cases without any definite inheritance pattern. It begins in childhood and the lesions are usually recurrent and become profuse and large with age. Systemic diseases have no role in the onset of lesions.

Conclusion:

Oral and topical retinoids in combination with emollients is the best treatment option.

Familial reactive perforating collagenosis: a clinical, histopathological study of 10 cases

OBJECTIVE

To study the clinical and histopathological features of familial reactive perforating collagenosis (RPC).

MATERIAL AND METHODS

Ten patients, including affected siblings in three, took part in the study. Parental consanguinity was present in one. Histopathological study was performed in all patients.

RESULTS

The eruptions appeared mainly during infancy or early childhood as papules showing a central plug, which subsided within 10 weeks. Areas commonly affected were the face, extremities and trunk. Rare sites were the scalp, ears and buttocks. One pregnant woman, in whom RPC had first manifested around puberty, had relatively widespread lesions. In those with seasonal variation, recurrences were seen a little more frequently in summer than in winter owing to the longer duration of the former. Histopathology confirmed the diagnosis with follicular involvement in four cases. In two patients whose backs were also affected, the lesions went unnoticed, as they were small and inconspicuous. In addition, the brother of a girl with RPC who claimed to be free of the dermatosis, had facial scars suggestive of RPC in the past.

CONCLUSIONS

Familial RPC can remain quiescent for a long period and the inherited defect not only shows extreme variability in expression but also demonstrates that lesions can be few and localized so as to escape notice in individuals and family members presenting with this benign, uncommon and self-subsiding dermatosis. In all patients topical retinoic acid was helpful in early regression. Sunscreens may mitigate the severity of RPC in those whose lesions are precipitated in summer but this needs further evaluation.

Manifestations of cutaneous diabetic microangiopathy

The etiologies of a variety of skin conditions associated with diabetes have not been fully explained. One possible etiological factor is diabetic microangiopathy, which is known to affect the eyes and kidneys in patients with diabetes. There are many mechanisms by which diabetes may cause microangiopathy. These include excess sorbitol formation, increased glycation end products, oxidative damage, and protein kinase C overactivity. All of these processes occur in the skin, and the existence of a cutaneous diabetic microangiopathy has been well demonstrated. These microangiopathic changes are associated with abnormalities of skin perfusion. Because the skin plays a thermoregulatory role, there is significant capillary redundancy in normal skin. In diabetic patients, loss of capillaries is associated with a decrease in perfusion reserve. This lost reserve is demonstrable under stressed conditions, such as thermal stimulation. The associated failure of microvascular perfusion to meet the requirements of skin metabolism may result in diverse skin lesions in patients with diabetes. Many skin conditions peculiar to diabetes are fairly rare. Necrobiosis lipoidica diabeticorum (NLD) and diabetic bullae occur very infrequently as compared with diabetic retinopathy and nephropathy. Conversely, there is a correlation between diabetic microvascular disease and NLD. This correlation also exists with more common skin conditions, such as diabetic dermopathy. This relationship suggests that diabetic microangiopathy may contribute to these conditions even if it is not primarily causal. Clinically, the major significance of diabetic cutaneous microangiopathy is seen in skin ulceration which is very common and has a major impact on diabetic patients. Many factors contribute to the development of diabetic foot ulcers. Neuropathy, decreased large vessel perfusion, increased susceptibility to infection, and altered biomechanics all play a role, but there is no doubt that inadequate small blood vessel perfusion is a major cause of the inability to heal small wounds that eventually results in ulcer formation. The accessibility of skin capillaries makes cutaneous diabetic microangiopathy an attractive model for research on the evolution of microvascular disease in diabetic patients.

The pathogenesis of the transepithelial elimination of the collagen bundles in acquired reactive perforating collagenosis. A light and electron microscopical study

Two cases of acquired reactive perforating collagenosis with poorly controlled diabetes mellitus were studied by histochemistry and by electron microscopy. In excoriated wound the necrotic mass on the bottom of the ulcer contained the collagen bundles which were continuous with the collagen bundles in the reticular layer. In the developing stage, the epidermis regenerated between the necrotic mass and the reticular dermis, and the collagen bundles in the reticular dermis were in continuity with those in the necrotic mass through the epithelial tunnels. The collagen in the epidermal channels did not degenerate ultrastructurally. In the mature lesion, collagen bundles being eliminated through the epidermis were surrounded by the fibroblasts at the basal cell layer. Collagen fibers were seen in the cytoplasm of these fibroblasts. From these findings, the mechanisms of the formation of the eruption in acquired reactive perforating collagenosis might be as follow: 1) In the developing stage, the regeneration of epidermis progresses between the necrotic mass and the reticular dermis, and among the collagen bundles. As a result, the collagen bundles remain in the channels of the epidermis. And then, 2) the regenerated epidermis makes the thick horny layer. As a result, the necrotic masses are lifted up and the collagen bundles are pulled up from the dermis through the epidermal channels.

Reactive perforating collagenosis--transepidermal elimination of type IV collagen

Reactive perforating collagenosis (RPC) is a rare skin disorder characterized by reddish papules with a central keratotic plug which appear mainly on the extensor aspects of the limbs. An idiopathic or classical variant has been delineated from an acquired one which occurs in diabetes mellitus and renal failure. Histopathological examination of the lesions shows transepidermal elimination of abnormally staining bundles of collagen. To clarify the origin of this collagenous material we performed an immunohistochemical study including biopsies of two patients with RPC, one classical and one acquired. Staining reactivity to antibodies against type IV collagen was observed, thus providing evidence that the collagen eliminated in RPC may be derived from the basement membrane zone.

Acquired perforating dermatosis of diabetes mellitus and renal failure: further ultrastructural clues to its pathogenesis

An ultrastructural study of a typical case of acquired perforating dermatosis in a patient with renal failure and diabetes mellitus is reported. Crystal-like microdeposits of an electron-lucid material were detected in the upper dermis, close to the transepidermal channel. Compact macrophage conglomerations surrounded the deposits, and a strong histiocytic response was present. Mononuclear inflammatory cells of "activated" type penetrated the acanthotic epidermis provoking basement membrane dissolution and widening of interkeratinocyte spaces. Collagen fibers were seen in the keratotic plug, indicating the process of transepidermal elimination. Our observation supports the hypothesis suggesting that some kind of storage phenomenon may be at the origin of perforating skin lesions in renal failure patients.

Ultrastructural changes in acquired perforating dermatosis

We performed ultrastructural studies of skin lesions in seven adults with acquired perforating dermatosis. Three of the patients had diabetes mellitus and two were undergoing hemodialysis. Lesions in an early stage showed exocytosis of inflammatory cells and alteration of elastic fibers. Lesions in an intermediate stage featured discontinuities of the basement membrane and aggregates of electron-dense material lateral to the perforated focus, together with dermal edema, scattered macrophages, and densely aggregated collagen fibers that focally filled the papillary dermis. Later-stage lesions showed fibroblasts in the dermis and degenerated elastic fibers within transepidermal channels. In most cases there was a single large epidermal channel lined by flattened epithelial cells, and containing a variety of cellular and extracellular materials. Small "secondary" channels without abnormal keratinization were also observed within the epidermis. The findings suggest that altered keratinization is limited to the immediate vicinity of well-formed transepidermal channels, and that exocytosis of inflammatory cells and alterations of elastica are early and possibly key changes in lesion development. The unexpected discovery of hair fragments in one case suggests that curled hairs may play a role in the pathogenesis of some cases of acquired perforating dermatosis.

A new treatment for acquired reactive perforating collagenosis

Acquired reactive perforating collagenosis is reported in an insulin dependent diabetic patient with renal impairment, managed successfully with surgical debridement and split skin grafting. The literature on treatment of reactive perforating collagenosis is reviewed.

Acquired perforating dermatosis: comparison of an acquired perforating dermatosis and perforation as an incidental histologic finding

A 66-year-old Japanese woman with a rare acquired perforating disorder, usually called adult-type reactive perforating collagenosis, is reported. The patient had poorly controlled diabetes mellitus with retinopathy under oral diabetic medication. She was found to have multiple papules and umbilicated nodules on the trunk and four extremities when she was admitted and examined for the origin of jaundice and severe pruritus of sudden onset. In the biopsy specimen, collagen fibers were observed to be eliminated from the dermis through epidermal tunnel-like perforations. No elastic fibers were eliminated, and serial sectioning of the specimen could not prove follicular perforation. Adenocarcinoma of the biliary duct was found to be the cause of the jaundice with pruritus. Although such cases are usually classified as acquired reactive perforating collagenosis of adult onset, proposed reclassification for acquired perforating disorders is discussed. Another case which also showed perforation and transepithelial elimination of both collagen and elastic fibers as an incidental histologic finding is described. Such elimination seems to be a not uncommon step in the formation of pruriginous eruptions. Therefore, these cases should be differentiated from acquired-type characteristic perforating disorders.

Reactive perforating collagenosis in a setting of double disaster: acquired immunodeficiency syndrome and end-stage renal disease

We report reactive perforating collagenosis in an intravenous heroin abuser with acquired immunodeficiency syndrome and end-stage renal disease. The literature on perforating disorders in patients with acquired immunodeficiency syndrome and the pathogenesis of reactive perforating collagenosis in this setting is reviewed.