Keratosis lichenoides chronica: A case report and focused overview of the literature

Abstract

over several weeks to months. 4 Additionally, response to antibiotics has been described in HKFE cases without associated BAK exposure. 1 For completeness, patch testing could have been considered to rule-out BAK allergic contact dermatitis; however, as the clinical features were characteristic for HKFE and our patients responded rapidly to initial therapy with amoxicillin-clavulanic acid, we did not pursue this.This observation in a mother-daughter pair, while not sufficiently robust to claim genetic aetiology, raises the possibility of genetic factors contributing to HKFE/GP, as also suggested by Robinson et al. (2019). 4 The microbiome and skin barrier function are genetically influenced and both are involved in HKFE pathogenesis. 3,4 The reversal of dysbiosis with antibiotics is an effective treatment strategy in conditions including erythrasma, confluent and reticulated papillomatosis, and also HKFE. 2 Positive bacterial cultures have been occasionally reported in HKFE, such as in Case 1, with organisms including Klebsiella pneumoniae, Streptococcus milleri and Coagulase-negative Staphylococci. 1,5 These organisms are normal skin commensals, and we believe the positive cultures reflect the state of dysbiosis rather than bacterial infection. However, further studies are required to characterise the altered microbiome of these patients, which may help determine the pathogenicity of organisms in HKFE.

Keratosis lichenoides chronica: a diagnosis to remember

“…Keratosis lichenoides chronica (KLC), also known as Nekam's disease, is a rare dermatosis of uncertain etiology. It appears most frequently in adults, with a peak of incidence in the 4 th decade and slight predominance in males 1,2,4 .…”

“…Clinically, KLC is characterised by lichenoid or keratotic violaceus papules arranged in a linear or reticulated pattern, especially on the limbs 4 . A seborrheic-like dermatitis eruption on the face is also a common finding of this disorder 4 .…”

“…Clinically, KLC is characterised by lichenoid or keratotic violaceus papules arranged in a linear or reticulated pattern, especially on the limbs 4 . A seborrheic-like dermatitis eruption on the face is also a common finding of this disorder 4 . Less frequent features include oral and genital ulcerative lesions, palmoplantar keratoderma and onychodystrophy which are found, respectively, in 50, 40 and 30% of cases 1,9,10 .…”

“…Regarding histology, typical findings are hyperkeratosis with focal parakeratosis, irregular acanthosis alternating with areas of atrophy, vacuolar degeneration of keratinocytes at dermoepidermal junction and chronic inflammatory infiltrate in the upper dermis consisting of lymphocytes, histiocytes and plasma cells (often around infundibula and acrosyringia) 4,5 .…”

“…The most effective treatment consists of oral retinoids at a dose of 0.3-0.6 mg/kg/day 2,11 , although complete responses are infrequent 11 . Phototherapy (psoralen plus ultraviolet A and narrow-band ultraviolet B) can be helpful, especially as an adjuvant treatment 4,11 . Topical treatment, as well as systemic steroids, other immunosuppressants and antimalarials, are usually ineffective 2,12 .…”