Pityriasis amiantacea is an
eczema
Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved can ...
tous condition of the scalp in which thick tenaciously adherent scale infiltrates and surrounds the base of a group of scalp hairs. It does not result in scarring or
alopecia
Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Inflammation or scar ...
.
[Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. .]
Pityriasis amiantacea was first described by Alibert in 1832.
[Alibert JL. La porrigine amiantacea.
Monographie des Dermatoses.
]Paris, France
Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. Si ...
, 1832: 293-5. Pityriasis amiantacea affects the scalp as shiny asbestos-like (amiantaceus) thick scales attached in layers to the hair shaft.
[Abdel-Hamid IA, Salah AA, Moustafa YM, El-Labban AM.
Pityriasis amiantacea: a clinical and etiopathologic study of 85 patients.
Int J Dermatol 2003; 42: 260-4.] The scales surround and bind down tufts of hair.
[Raquel M. Shalev, Arnon D. Cohen, Evgeny Medvedovsky, Stella Sashavinsky,
Theodore Tchetov and Daniel A. Vardy.
Pityriasis Amiantacea Associated with Staphylococcus aureus Super-infection in Bedouin Patients.
]Microbial Ecology
Microbial ecology (or environmental microbiology) is the ecology of microorganisms: their relationship with one another and with their environment. It concerns the three major domains of life—Eukaryota, Archaea, and Bacteria—as well as viru ...
in Health and Disease 2004; 16: 218-221 The condition can be localised or covering over the entire scalp. Temporary alopecia and
scarring alopecia
A scar (or scar tissue) is an area of fibrous tissue that replaces normal skin after an injury. Scars result from the biological process of wound repair in the skin, as well as in other organs, and tissues of the body. Thus, scarring is a na ...
may occur due to repeated removal of hairs attached to the scale. It is a
rare disease
A rare disease is any disease that affects a small percentage of the population. In some parts of the world, an orphan disease is a rare disease whose rarity means there is a lack of a market large enough to gain support and resources for discov ...
with a female predilection.
Diagnosis
Pityriasis amiantacea can easily be misdiagnosed due to its close resemblance to other scalp diseases such as
psoriasis
Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by raised areas of abnormal skin. These areas are red, pink, or purple, dry, itchy, and scaly. Psoriasis varies in severity from small, localized patches to complete ...
,
seborrhoeic dermatitis
Seborrhoeic dermatitis, sometimes inaccurately referred to as seborrhoea, is a long-term skin disorder. Symptoms include red, scaly, greasy, itchy, and inflamed skin. Areas of the skin rich in oil-producing glands are often affected including the ...
or
lichen planus
Lichen planus (LP) is a chronic inflammatory and immune-mediated disease that affects the skin, nails, hair, and mucous membranes. It is not an actual lichen, and is only named that because it looks like one. It is characterized by polygonal, fla ...
. However, in pityriasis amiantacea the scales are attached to both the hair shaft and the scalp. Pityriasis amiantacea may be present with other inflammatory conditions such as
atopic dermatitis
Atopic dermatitis (AD), also known as atopic eczema, is a long-term type of inflammation of the skin (dermatitis). It results in puritis, itchy, red, swollen, and cracked skin. Clear fluid may come from the affected areas, which often thickens o ...
or seborrhoeic dermatitis and sebaceous scales and alopecia can occur. According to Bolognia's textbook "Dermatology,"
[Bolognia et al. Dermatology, Second Edition, pg 122] this rare condition is most often combined with psoriasis, but it may also develop as secondarily infected atopic dermatitis, seborrheic dermatitis, and/or tinea capitis.
Treatment
The bacteria staphylococci are present in the majority of cases.
Treatment with systemic antibiotics and
coal tar
Coal tar is a thick dark liquid which is a by-product of the production of coke and coal gas from coal. It is a type of creosote. It has both medical and industrial uses. Medicinally it is a topical medication applied to skin to treat psoriasi ...
shampoo can completely clear the condition when ''
Staphylococcus aureus'' bacteria are found.
Fungal infections
Fungal infection, also known as mycosis, is disease caused by fungi. Different types are traditionally divided according to the part of the body affected; superficial, subcutaneous, and systemic. Superficial fungal infections include common ti ...
such as
tinea capitis
Tinea capitis (also known as "herpes tonsurans", "ringworm of the hair", "ringworm of the scalp", "scalp ringworm", and "tinea tonsurans") is a cutaneous fungal infection (dermatophytosis) of the scalp. The disease is primarily caused by dermatoph ...
are known to mimic the symptoms of the condition
[M. Ginarte, M. Pereiro Jr, Virginia Ferna´ndez-Redondo and Jaime Toribio
Case Reports. Pityriasis amiantacea as manifestation of
tinea capitis due to Microsporum canis.
mycoses 2000, 43, 93–96
] and can be cleared with antifungal treatment.
See also
*
List of cutaneous conditions
Many skin conditions affect the human integumentary system—the organ system covering the entire surface of the body and composed of skin, hair, nails, and related muscle and glands. The major function of this system is as a barrier against t ...
References
External links
{{Papulosquamous disorders
Conditions of the skin appendages