Dermatosis neglecta.

Dermatosis neglecta is the name of a skin condition characterized by papules and polygonal plaques, which are sometimes warty, brownish and hyperpigmented, adherent and symmetric, though removable with ethyl or isopropyl alcohol. It occurs due to inadequate skin cleansing causing accumulation of sebum, sweat, keratin and impurities. Its occurrence, though little reported, is frequent. The main differential diagnosis is the Terra firma-forme dermatosis. The treatment is simple, with exfoliation, moisturizing and even rubbing of alcohol. Causes of negligence on the patient's side, which can range from hygiene carelessness to psychiatric disorders, local hypersensitivity, limbs negligence or motor paralysis, should be investigated. We illustrate the case of dermatosis neglecta in a 45-years old patient admitted with pulmonary sepsis.

INTRODUCTION

Dermatosis neglecta, denominated so for the first time in 1995 by Poskit et al, [1] is an entity that derives from the progressive accumulation of sebum, sweat, keratin, cellular debris and exogenous impurities, resulting in papules, polygonal plaques and hyperpigmented adherent, localized, verrucous lesions, symmetrically distributed mainly on torso, shoulders and neck, which may be cleared with some difficulty with soap and water, and completely removed with alcohol. [1-3] Lesions originate from a lack of or inadequate cutaneous cleaning and exfoliation, either by neglect or as a result of some disability.[1] Some authors cite motor or sensory impairments, pain/hyperesthesia and immobility secondary to trauma, surgery or nerve palsy as the main triggers. [4] There are also reports describing dermatosis neglecta as a form of dermatitis artefacta.[1,2]

The diagnosis is made by careful dermatological examination and a propaedeutic test consisting of local friction with ethyl or 70% isopropyl alcohol, which completely clears the lesions without sequelae, displaying normal skin underneath the scrubbed area.[1] Histopathology, rarely necessary, shows acanthosis, papillomatosis, hyperkeratosis and lamellar orthokeratosis. [3]

Although employed as synonyms, dermatosis neglecta must be differentiated from Terra firma forme dermatosis, a condition described in 1987 by Duncan et al. that probably results from a keratinocyte maturation disorder leading to accumulation of keratin, sebum, sweat and melanin, with reports of adequate hygiene in the affected area (Chart 1). [5] There is some controversy whether these two entities might represent different spectrums of the same pathology. [5]

CHART 1

Comparison between dermatosis neglecta and Terra firma-forme

Neglecta	Terra firma-forme
Neglected hygiene	Hygiene reported as normal
Any age range	More prevalent among children
Crusted and scaly	Predominantly macular
Lamellar hyperkeratosis	Whorled hyperkeratosis
May improve with soap and water	Removed only with alcohol

Other differential diagnoses are: confluent and reticulated papillomatosis of Gougerot and Carteaud, pityriasis versicolor, acanthosis and pseudoacanthosis nigricans, psoriasis, ichthyosis, seborrheic keratosis, epidermic nevus, asymptomatic skin darkening secondary to friction in extensor areas and post-inflammatory hyperpigmentation. [1,3]

Beside hygiene counseling, treatment may include the propaedeutic test itself, that is alcohol rubbing, and the use of creams made with urea, ammonium lactate and salicylic acid, association of exfoliants and mechanical removal of crusts. [1,3] Prognosis is very good, without sequelae and with low rates of relapse, when triggering factors are eliminated.

CASE REPORT

Forty-five year-old single male, admitted to the internal medicine service due to sepsis with pulmonary focus, was referred for dermatologic evaluation of slightly pruritic, yellowish-brown, confluent, crusted papules, clustered on the dorsal and lateral areas of the toes bilaterally (Figure 1). The lesions were noticed during hospitalization. The patient was lethargic and somewhat anhedonic.

FIGURE 1

Dermatosis neglecta. A. Yellowish-brown crusted papules clustered on the dorsal area of the toes. Detail of a lesion: on the dorsal area of the third left toe’s distal phalanx. B. Lesion dermoscopy: well-delimited, brownish lesions, with a pattern similar to cobblestones, superfi - cial desquamation and absence of pigment network. C. Virtually normal skin after rubbing a 70% ethylic alcohol-soaked gauze on the third left toe. D. Dermoscopy after friction: discreet, diffuse and uniform white spots

After dermatologic assessment of the lesions, diagnostic hypotheses were paraneoplastic syndrome manifesting as seborrheic dermatosis, corresponding to Leser-Trélat syndrome and dermatosis neglecta. A propaedeutic test consisting of rubbing a 70% ethylic alcohol-soaked gauze over the area resulted in the removal and resolution of lesions, displaying healthy skin underneath, without pigmentary disorders (Figures 1 and 2).

FIGURE 2

Dermatosis neglecta. Rubbing with 70% ethylic alcohol-soaked gauze

DISCUSSION

As there was no certainty about the timing of lesions onset in the case reported, it was impossible to determine whether they arose from an impairment in general condition during the episode of sepsis and the reduction of friction during bathing, or if the patient already had these lesions previously due to poor hygiene in the toes' area.

Dermatosis neglecta should be recalled as a possible diagnosis amongst pathologies that course with papillomatosis, hyperpigmentation and crusts. Symptoms are few, although there may be great aesthetic discomfort. Strenuous investigations, such as laboratory tests and biopsies can be avoided with the application of ethyl or isopropyl alcohol on a gauze pad or cotton swab on the area, a simple and quick test that must only be recollected.

Dermoscopy can be useful in dermatological examination by showing the absence of structures common in differential diagnoses, such as seborrheic keratoses. Furthermore, the yellowish-brown coloration indicates the presence of keratin accumulated on the surface, which is expected in dermatosis neglecta.

Treatment starts already at diagnosis and patient counseling on the cause of lesions must be honest and free of judgment, explaining why the friction is necessary and also about the possibility of recurrence if the trigger factors are not removed.

Dermatosis neglecta is easily diagnosed and treated and knowledge about it is relevant for the dermatologist as well as for the general physician, since it may indicate a primary trigger, ranging from hygiene neglect to psychiatric disorders, sensibility disorders, neuralgia, or paralysis.