Scalp Itch: A Systematic Review

Abstract

ated with a desire to scratch [1] . Just like skin pruritus, its etiology may be of dermatological or non-dermatological origin. It is common for the dermatologist to encounter patients with no evident cause of scalp pruritus, making it a distressing situation for both the clinician and the patient. The aim of this paper is to review the clinical signs of the most common causes of scalp itch and other less common causes that must be considered in a systematic approach to scalp pruritus. Materials and MethodsWe performed a MEDLINE search through PubMed (1975PubMed ( -2017, using the terms scalp itch and scalp pruritus and included clinical trials, review articles, case series, and case reports to search for the causes of scalp itch. PathophysiologyAlthough various pathogenic etiologies contribute to scalp pruritus, the scalp itself has distinct neuroanatomy and vasculature, specific neuromediators and corresponding receptors, as well as the presence of scalp sebum and microflora, which are all properties that may explain its tendency to be implicated in patients who complain of itch. Keywords Scalp · Itch · Pruritus · Seborrheic dermatitis · Contact dermatitis · Anxiety · Lichen planopilaris · Lice · Pediculosis · Psoriasis · Trichoscopy AbstractScalp itch is a frequent complaint in the dermatological setting. It is common for the dermatologist to encounter patients with no evident cause of scalp pruritus, making it a distressing situation for both the clinician and the patient. The aim of this paper is to propose a systematic approach to scalp itch, which classifies scalp pruritus into two types: (1) with or (2) without dermatological lesions, and presence or absence of hair loss. Also, it is important to think first about the most common causes and then rule out other, less common etiologies. The acronym SCALLP and the five steps for scalp evaluation (listen, look, touch, magnify, and sample) are useful tools to keep in mind for an assertive approach in these patients.

Compared to Controls, Individuals with Lichen Planopilaris Have More Depression, a Lower Self-Esteem, and a Lower Quality of Life

“…Furthermore, it is estimated that up to 7% of the adult population, and often women, suffer from PCA [4]. LPP is characterized by follicular hyperkeratosis, perifollicular erythema, and a loss of follicular orifices [1, 5]. The underlying pathophysiology is not fully understood and appears to be multicausal; while there is evidence that the loss of positive stem cells for CK15 (cytokeratin 15) leads to LPP [6, 7], there is also scientific agreement that T lymphocytes appear to influence unknown antigens of keratinocytes and destroy these cells.…”

“…Typically, individuals with LPP suffer from hair loss, itching, erythema, scaling, and burning [5]. Thus, on a behavioral level, individuals with LPP have an increased risk of scratching the itchy parts of the scalp.…”

Trichoscopy in the Differential Diagnosis of Pseudonits

“…They can present as whitish scales, frequently seen in seborrheic dermatitis (Fig. 2) or psoriasis of the scalp, appearing at trichoscopy as easily detachable white, bizarrely shaped, amorphous structures on the hair shaft; although generally easily recognized at clinical examination, in children they can be misdiagnosed as nits [11]. Hair casts, also known as peripilar keratin casts, that clinically appear as white, tubular, freely movable structures encircling the proximal hair shafts of the scalp, and that may be primary/idiopathic when there is no associated scalp condition (Fig.…”

Patrones tricoscópicos de las alopecias cicatrizales

“…La tricoscopia en etapas iniciales puede revelar signos de una alopecia no cicatrizal y algunos datos de alopecia areata, como pelos rotos, puntos negros y pelos en exclamación. En etapas más avanzadas se reconocen de manera característica estructuras en "burbuja de jabón" o puntos amarillos en 3D que son en realidad tallos pilosos distróficos; también son posibles politriquia, puntos negros, puntos blancos que corresponden a tractos fibróticos orientados verticalmente, aberturas foliculares vacías sobre fondo blanquecino, áreas blancas cicatrizales y zonas de eritema; los vasos sanguíneos se observan con un halo blanquecino 5,44 (Fig. 5).…”

“…En general, la patogenia de las alopecias es controvertida; el blanco del proceso inflamatorio es el infundíbulo folicular, por lo que el daño al folículo tiende a ser irreversible con la evolución de la enfermedad; algunos casos están relacionados con síntomas como prurito o ardor 4,5 .…”