Trichoscopy of inflammatory conditions

Trichoinflamoscopy

The following page covers the features of inflammatory skin disease using trichoscopy.

Seborrheic dermatitis

Seborrheic dermatitis is a common chronic relapsing inflammatory skin condition with a predilection for areas rich in sebaceous glands (i.e. the scalp, central face, and anterior chest are most affected). The disorder is characterised by scaling with poorly defined erythematous patches and plaques. Young adults are more frequently affected, and men are affected more than women.

The most frequent trichoscopic findings include:

• Multiple, thin, arborizing vessels are observed; recently, comma vessels have also been reported.
• Featureless areas with no particular vascular pattern may be found
• Adherent yellow scales and interfollicular white scales
• Interfollicular oily material
• Interfollicular pustules
• Honeycomb pigment pattern
• Concretions
• Yellow dots
• “Dandelion sign” described as yellow dot surrounded by glomerular and comma vessels
• “Cherry blossom sign” described as arborizing vessels with glomerular and comma vessels surrounding them.

Dermoscopic image of diffuse yellowish greasy scales in a male patient with seborrhoeic dermatitis 

Dermoscopic image of seborrhoeic dermatitis showing adherent yellowish scales and interfollicular oily material on the scalp of a male infant (SD-patient1)

Dermoscopic image of hair casts represented by detached hyperkeratotic and parakeratotic cells of the inner root sheath which surrounds the hair shaft 

Psoriasis

Psoriasis is a chronic inflammatory cutaneous disorder with multisystem involvement. The scalp is the most commonly affected site (50–80% of psoriasis patients) and may be the first or only disease manifestation.

Scalp psoriasis is characterised by sharply bordered, erythematous lesions covered by silver or white scales. The lesions often spread over the anterior hairline into the forehead and may also affect the retro-auricular region.

Trichoscopic evaluation of scalp psoriasis

Evaluation of scalp psoriasis is based on the evaluation of vascular alterations.

At low magnifications:

• Red dots and globules with regular distribution are observed
• White/white-silver dry scales is a very frequent finding
• Hidden hair and signet ring vessels are recently reported signs supporting the diagnosis of psoriasis.

At high magnifications:

• Glomerular vessels arranged into rings or lines
• Other types of capillaries (linear looped, lace-like, comma vessels) may be present.

Systemic sclerosis (SSc)

Systemic sclerosis is an autoimmune connective tissue disease. Different factors are incorporated in the pathogenesis of the disease including; small vessel vasculopathy, production of autoantibodies, and fibroblast dysfunction.

Clinical manifestations and prognosis are variable according to the degree of cutaneous and systemic organs involvement. Clinical subtypes include limited cutaneous SSc, diffuse cutaneous SSc, and SSc without skin involvement.

Trichoscopic examination of the forehead area

Trichoscopic findings include:

• Polymorphous pattern of blood vessels, including arborizing vessels similar to the pattern observed in DLE, spider vessels, and capillary loops
• Telangiectasia detected in the scalp of systemic sclerosis patients was also observed in other sites of the body
• ‘Salt and pepper’ areas are a recently reported sign
• Loss of follicular openings
• Pili torti
• Black dots
• Broken hairs.

Dermatomyositis

Dermatomyositis is a chronic inflammatory disease characterised by proximal myopathy, and cutaneous, cardiac, pulmonary, and gastrointestinal affection. Common cutaneous signs include Gottron's papules, heliotrope rash, mechanic's hand, and poikiloderma.

Trichoscopic findings

• Erythematous violaceous areas.
• Enlarged tortuous and bushy capillaries.
• Interfollicular scales.
• Interfollicular and perifollicular pigmentation.
• Scalp atrophy.
• Tufting with three or more hair shafts emerging together surrounded by peripilar cast.