📚 Question Bank

Alopecia areata and secondary syphilis cause non-scarring (non-cicatricial) alopecia. Common conditions causing scarring (cicatricial) alopecia include:

• Discoid lupus erythematosus (DLE)
• Pseudopelade of Brocq
• Scleroderma
• Favus
• Kerion
• Lichen planopilaris
• Folliculitis decalvans.

The patient has a history of itching and mild discharge and examination shows a well-demarcated patch of alopecia, with scaling and broken hair shafts. This is characteristic of tinea capitis.

Though the diagnosis is clinical, a KOH mount is used for confirmation.

Scrapings from the edge of a lesion are transferred to a slide, to which KOH is added. It is then examined under the microscope for the presence of hyphae, as shown below.

Tinea capitis is a dermatophyte infection primarily occurring in children. Clinical features of tinea capitis are patchy hair loss, scaling, tender lymphadenopathy, and in severe cases, there might be pustules and crusting of the affected area along with sinus formation.

The clinical variants of tinea capitis are:

• Endothrix - a non-inflammatory type in which multiple black dots are present within the areas of alopecia. It is most commonly caused by T. tonsurans and T. violaceum.
• Ectothrix - a mild inflammatory type in which single or multiple scaly patches with hair loss are seen. Microsporum audouinii, M.canis, M.equinnum, and M.ferrugineum cause ectothrix infection.
• Kerion - a severe inflammatory type that presents with an inflammatory mass with thick crusting and matting of hair with pus and sinus formation. It is commonly caused by T.
• verrucosum and T. mentagrophytes.
• Favus - is characterized by the presence of yellowish, cupshaped crusts known as scutula that develop around hair follicles. It is caused by T. schoenleinii

Treatment:

• Terbinafine: lt;10 Kg- 62.5 mg; 10-20 kg - 125 mg; gt;20 kg- 250 mg, all given daily for 4
• weeks.
• Itraconazole: 2-4 mg/kg/day for 4-6 weeks.

The given image is characteristic of trichotillomania. It is an obsessive-compulsive disorder characterized by compulsive hair pulling. Ingestion of the plucked hair is called trichophagia. Rarely, the resulting hairball called trichobezoar can cause intestinal obstruction.

The characteristic features are,

• Varying lengths of hair and absence of complete hair loss in the patch
• Orentreich or Friar Tuck or Tonsure sign: Loss of central area (easier to pull) and sparing of margins of the scalp.
• Broken hair shafts
• No scarring.

Histopathological examination shows,

• No inflammation
• Peribulbar, intraepithelial and perifollicular hemorrhages
• Intrafollicular pigment casts.

Trichotillosis is the newer term as it is not a 'mania'. It shares some features with the OCD spectrum of disorders. It is usually associated with other psychiatric conditions.

Option A: Alopecia areata shows well-circumscribed patches of complete hair loss with sparing of white hair, as shown below.

Option B: Pseudopelade of Brocq is a scarring alopecia that produces small round or oval patches of smooth alopecia, described as footprints in the snow.

Option C: Telogen effluvium can occur 2-3 months after systemic stress such as surgery or illness, but it causes diffuse hair loss, not patchy as in this patient.

Bamboo hair is seen in Netherton syndrome.

It presents with atopy, recurrent skin infection, and an increased risk of skin cancer. It has two characteristic features, namely:

• Ichthyosis linearis circumflexa - a rare form of ichthyosis with scaling and plaques.
• Trichorrhexis invaginata or bamboo hair - characterized by invagination of the distal hair shaft into the proximal portion. It is also called golf-tee or ball and socket appearance as seen below.

Option A: Trichorrhexis nodosa is associated with trauma to the hair shaft and arginosuccinic aciduria. It causes node formation and fractures which results in the thrust paintbrush appearance seen below as if two paintbrushes are rubbing against each other.

Option C: Menkes kinky hair syndrome is an X-linked recessive disorder of copper metabolism. It is associated with pili torti or twisted hairs, seen in the first image, and monilethrix or beaded hair, seen in the second image.

Option D: Uncombable hair syndrome produces a characteristic triangular cross-section of hair and longitudinal groove along one side which contributes to its hair stiffness.

The marked structure is the lunula, which is the whitish half-moon-shaped structure between the free margin of proximal nail fold and nail bed.

The various parts of the nail include:

• Nail plate: Durable, chemically resistant, partially translucent keratinized structure which grows throughout life.
• Proximal nail fold: Cutaneous folded structure providing a visible proximal border of nail fold, continuous with the cuticle.
• Lateral nail fold: Cutaneous folded structures providing the lateral borders to the nail.
• Lunula: Convex margin of intermediate nail matrix seen through the nail.
• Eponychium: Small band of epithelium extending from the proximal nail fold and adhering to the dorsal aspect of the nail plate.
• Cuticle: Thin layer of dead tissue which forms a seal between the nail plate and eponychium to prevent pathogens from infecting the matrix area.
• Nail Bed: The vascular bed upon which nail rests extending from the lunula to the hyponychium.
• Hyponychium: Cutaneous margin underlying free nail, bordered distally by the distal groove.

Koilonychia is not seen in megaloblastic anemia. It refers to a flattening or concavity of the dorsal part of the nail producing a spoon shape. It can occur in the following conditions

• Iron-deficiency anemia
• Hemochromatosis
• Raynaud’s disease.

Psoriasis and dermatophytes also can mimic koilonychia

The following image also shows koilonychia or spoon-shaped nails:

The given image shows dorsal pterygium, which is a characteristic nail finding in lichen planus.

It is a wing-shaped deformity of the dorsal nail due to a central fibrotic band that divides the nail into two parts in the proximal area.

Ventral pterygium or pterygium inversum unguis refers to the adherence of the distal portion of the nail bed to the ventral surface of the nail plate. It can be idiopathic or due to trauma, systemic sclerosis, Raynaud phenomenon. It makes the trimming of nails very painful.

This image shows Beau’s lines which are generalized transverse grooves on the nail which may be full or partial thickness. They usually occur a few weeks after a precipitating systemic event like MI, measles, mumps, or pneumonia.

Isolated transverse grooves in individual nails may occur due to trauma, inflammation, or neurological events.

Option B: Mees or Aldrich–Mees lines or Leukonychia striata are white lines that occur as a 1–2 mm wide transverse band is in the arcuate form of the lunula. They are associated with arsenic and lithium poisoning as well as renal failure.

Option C: Lindsay nails or half-and-half nails are a rare finding where the proximal portion of the nail is white and the distal half is pink, with a sharp line of demarcation between the two halves. They are specific for renal failure.

Option D: Trachyonychia is roughening of nails observed in alopecia areata.

The given image shows paired white bands parallel to the lunula called Muehrcke’s lines, which are a specific finding of hypoalbuminemia. They are reversible with albumin infusion.

Option A: In congestive heart failure, leukonychia or Terry’s nails are seen. Option B: In renal failure, half and half nails are seen.

Option D: In iron-deficiency anemia, koilonychia is seen.

The condition shown in the above image is yellow nail syndrome. It is associated with lymphedema, which is non-pitting.

It is a rare disease characterized by the classical triad of:

• Yellow dystrophic nails, due to thickening of nails
• Primary lymphedema (due to underdevelopment of the lymphatic vessels)
• Pleural effusion

Other common manifestations include chronic rhinosinusitis, chronic bronchitis, bronchiectasis, increased risk of malignancy.

It is also associated with D-penicillamine therapy and nephrotic syndrome. Hypothyroidism and AIDS may show yellow nails, but it is unclear whether this is due to yellow nail syndrome or simply due to retarded growth.

The woman is suffering from a glomus tumor. It is a benign tumor of the myoarterial glomus.

It is seen at 30-40 years of age in adults. Multiple tumors are more common in children than adults. It can occur in the hands, head, neck, penis or even internal organs.

It presents as a pink or purple nodule. Pain is the predominant feature, especially in nail tumors. It is provoked by temperature change and direct pressure. On examination, a bluish-red hue is seen in the following image. Surgical excision is curative as recurrence is rare.

Option A: Subungual hematoma is caused by acute heavy injury or chronic repeated trauma. It causes brownish-grey discoloration of the nail, as seen below.

Option B: Herpetic whitlow is an HSV infection that occurs following minor trauma. It affects the nail and periungual region, as seen below.

Option C: Subungual exostosis is a benign tumor that causes reddish onycholysis of the nail with variable pain, as seen below.

Nail patella syndrome (NPS) is an autosomal dominant condition causing nail and bone dysplasia. It is characterized by the following:

• Triangular lunula instead of a crescent-shaped lunula
• Patella is small, irregular, or absent
• Iliac horns are bony protrusions from the iliac bone laterally and posteriorly.
• The following image shows a dysplastic nail with triangular lunula.

The following AP radiograph shows a hypoplastic patella in a patient with NPS.

The following AP radiograph of the right iliac crest shows a bony exostosis or posterior iliac horn

(white arrow), which is pathognomonic of NPS.

The shown nail findings are characteristic of Darier's disease. They include:

• Longitudinal erythronychia
• Longitudinal leukonychia
• Distal Vshaped nicks.

Darier's disease or keratosis follicularis or dyskeratosis follicularis, is an autosomal dominant condition arising from mutations in the ATP2A2 gene which affects the SERCA2 calcium pump. It presents with greasy hyperkeratotic papules and plaques in seborrheic regions. Neuropsychiatric

features such as depression, psychosis and mental retardation may also occur. Option B: Hailey-Hailey disease presents with longitudinal leukonychia.

Option C: Lichen planus presents with dorsal pterygium.

Option D: Psoriasis causes the pathognomonic oil drop sign. It is a yellow-red discoloration in the nail bed resembling a drop of oil.

This patient has green nails or chloronychia, a painless condition caused by infection with Pseudomonas aeruginosa.

Pseudomonas may colonize the nail following onycholysis (painless separation of the nail from bed) which occurs due to frequent wetting or wearing of gloves causing maceration and minor trauma due to long nails or manicures. The green color is due to pyoverdin and pyocyanin, produced by P. aeruginosa.

Though it is harmless for the patients, it may spread to other immunosuppressed individuals. Hence, these patients should not work in hospitals, kitchens and other places where they are likely to spread the infection to others.

Treatment is with fingertip bath in white vinegar, bleach, or topical gentamicin. Option A: Klebsiella colonization can cause greyish discoloration of nails.

Option B: Minocycline is one of the most common antibiotics used by dermatologists due to its anti-inflammatory properties. It causes a bluish-grey discoloration of nails.

Option C: Onychomycosis causes whitish-yellow discoloration and is painful in later stages.

The given clinical image of hair seen under polarising microscopy reveals tiger tail banding

(alternating light and dark bands) characteristic of trichothiodystrophy.

Trichothiodystrophy is an autosomal recessive condition causing defective DNA repair. It causes brittle sulfur-deficient hair, photosensitivity, ichthyosis and systemic involvement. Unlike xeroderma pigmentosum (a similar condition with defective DNA repair), there is no risk of skin cancer.

Option A: Trichorrhexis nodosa is associated with node formation and fractures. The classic appearance, shown in the image below, is known as thrust paintbrush appearance as if two paintbrushes are rubbing against each other. It is associated with trauma to the hair shaft and arginosuccinic aciduria.

B- Trichorrhexis invaginata or bamboo hair is characterized by invagination of the distal hair shaft into the proximal portion. It is seen in Netherton's syndrome. It is also called golf-tee or ball and socket appearance as seen below.

Option D: Monilethrix, seen in the image below, is characterized by beaded hair and is fragile at the constricted sites. It occurs as an isolated condition or can occur in Menkes disease.

The color of the human skin does not depend on the number of melanocytes. The color of the skin depends on the following:

• Amount of melanin inside melanocytes
• Number and size of melanosomes
• Degree of transfer of melanin into keratinocytes

The ratio of the epidermal melanin unit is 36 keratinocytes : 1 melanocyte.

The color of the skin is due to the pigment melanin synthesized by melanocytes. Melanocytes are dendritic cells derived from neural crest cells and are present in the epidermis' stratum basale.

Each melanocyte synthesizes melanin and packs it in cell organelles to form melanosomes. These melanosomes are transferred through dendritic processes to 36 keratinocytes forming the ‘epidermal melanin’ unit.

White forelock is quite common in piebaldism.

Piebaldism is an autosomal dominant benign condition. Mutations are in the cKIT gene. Well-defined irregular hypopigmented macules with an absence of melanocytes are seen.

Leucotrichia is associated with the depigmented macules. Small spots of hyperpigmentation are also seen within hypopigmented patches or on normal skin. It is often associated with a V-shaped leucoderma on the mid-forehead.

Epidermal cell or skin grafting is the treatment.

Piebaldism can be distinguished from vitiligo because of the neonatal presence of white patches. The images below show patients with piebaldism.

The child has skin findings suggestive of piebaldism, which along with sensorineural deafness point towards Waardenburg syndrome.

It is an autosomal dominant disorder that is characterized by:

• White forelock
• Hypopigmented patches
• Heterochromia iridis
• Sensorineural deafness.

The image below shows clinical associations of the Waardenburg syndrome.

Option B: Hermansky–Pudlak syndrome is a rare type of oculocutaneous albinism associated with a hemorrhagic diathesis. The disease results from abnormal biogenesis of lysosome-related organelles with impaired melanosome maturation and absent dense bodies in thrombocytes.

Option C: Chédiak–Higashi syndrome is a rare autosomal recessive disorder characterized by hypopigmentation of the skin and eye, immunodeficiency, and possibly neurological symptoms.

Option D: Oculocutaneous albinism (OCA) is a rare autosomal recessive genetic disorder characterized by generalized depigmentation of the skin, hair, and eye caused by a deficiency in melanin biosynthesis.

The peripheral smear shows giant inclusions in polymorphonuclear neutrophils, which along with oculocutaneous albinism is suggestive of Chediak-Higashi syndrome.

It is an autosomal recessive disorder due to loss-of-function mutation of the LYST gene encoding a protein known as lysosomal trafficking regulator.

Clinical features occur due to defective transport of cell products. These include:

• Significant pyogenic infections
• Albinism (due to abnormalities of melanocytes)
• Neurological abnormalities
• Progressive intellectual decline
• Cranial nerve palsies
• Decreased deep tendon reflexes
• Tremor
• Abnormal gait (nerve cell dysfunction),
• Bleeding (due to platelet dysfunction).

Peroxidasepositive giant inclusions are seen in leukocytes. The only curative treatment available for Chédiak–Higashi syndrome is bone transplantation.

Oculocutaneous albinism is not due to tryptophan deficiency but is due to tyrosinase deficiency.

It is a rare autosomal recessive disorder characterized by generalized depigmentation of the skin, hair, and eye. Ophthalmological anomalies are also noted. It is caused by a deficiency in melanin biosynthesis, but melanocytes are normally present and distributed.

It is caused by mutations in TYR, encoding the tyrosinase gene.

Significant photophobia may be present. Iris translucency is demonstrable by slit-lamp examination.

Sun protection is mandatory to avoid skin sunburns and skin cancers with a special emphasis on patients living in high UV risk environments. Early referral to an ophthalmologist is mandatory. Dark glasses are important to protect the eyes and prevent photophobia.

The image is suggestive of vitiligo. The pathological basis of vitiligo is the loss of melanocytes.

Vitiligo is a common form of localized depigmentation. It is characterized by milkywhite sharply demarcated macules. It is an acquired condition resulting from the autoimmune destruction of dopa-positive melanocytes in the basal layer of the epidermis.

Vitiligo can begin at any age but in the majority of cases becomes apparent in the third

decade. The prevalence is most probably the same in both sexes or a slight female preponderance.

Electron microscopy studies confirm the loss of melanocytes. Wood's lamp examination shows milky-white fluorescence.

Koebner phenomenon defined as the development of lesions at sites of trauma to uninvolved skin of patients with cutaneous diseases is a wellknown phenomenon in vitiligo.

The patient has vitiligo. Amongst autoimmune diseases, the strongest association of vitiligo is with thyroid disorders (hyperthyroidism and hypothyroidism).

Other disorders associated with vitiligo are:

• Pernicious anemia
• Addison's disease
• Diabetes type I
• Myasthenia gravis
• Alopecia areata
• Uveitis
• Chronic mucocutaneous candidiasis
• Autoimmune polyendocrine syndromes (types I and II)

The clinical scenario suggests a diagnosis of vitiligo. Cyclosporine is not a treatment option for vitiligo. There is not enough evidence of its benefits and more potential side effects.

Treatment options for vitiligo:

• Topical agents:
• Topical corticosteroids
• Calcineurin inhibitors - tacrolimus
• Vitamin D analogs - calcitriol
• Systemic agents:
• Corticosteroids
• Azathioprine
• Phototherapy:
• PUVA
• PUVASol - sunlight
• NBUVB - narrow band UV B radiation at 311nm
• Targeted phototherapy using excimer laser 308nm
• Surgical treatment:
• Ultrathin partial thickness skin grafting
• Non-cultured autologous melanocytic transfer
• Cultured autologous melanocytic transfer

Note: Surgical treatment is usually reserved for patients with stable (a period of disease inactivity ranging from six months to two years) vitiligo who failed to respond to non-surgical treatment.

The image shows photochemotherapy (PUVA therapy), used for the treatment of vitiligo. It causes suppression of T lymphocyte action.

The UVA spectrum is 320-400 nm. When it is used in combination with an oral or

topical psoralen photosensitizer, it is known as PUVA therapy. The most frequently-used oral

psoralens are 8methoxy psoralen (8MOP) and 5methoxy psoralen (5MOP).

The mechanisms of action of PUVA:

• Inhibition of DNA replication - DNA crosslinking by psoralen photoadducts
• Langerhans cell depletion
• Immunosuppressive effects on Tlymphocyte function
• Stimulation of melanogenesis
• Migration and the restoration of Th1›/regulatory T-cell imbalance in psoriasis
• Indications of PUVA therapy:
• Psoriasis
• Atopic eczema
• Vitiligo
• Polymorphic light eruption
• Cutaneous T cell lymphoma

The UVB part of the spectrum is 280-320 nm. Lamps utilizing the 311-313 nm frequencies are called narrowband UV (NBUVB). UVB phototherapy has antiinflammatory, immunosuppressive, and cytotoxic properties.

Vitiligo may respond both to NBUVB and PUVA. NBUVB is more effective than PUVA but the response is variable and treatment usually has to be prolonged, often over many months to a year or more.