• The initial lesion, known as the herald patch, mother’s patch, or medallion patch, is seen as well-demarcated erythematous patch with a collarette of scales in the periphery typically over the trunk, neck, or upper extremities.
• Within a few days to 2 weeks, this is followed by the emergence of crops of oval, erythematous plaques with a peripheral collarette of scales and central clearing over the trunk, neck, and extremities.
• Lesions on the trunk align with the skin cleavage lines, producing a “Christmas tree” pattern

• Infantile scabies: Papular urticaria, eczema herpeticum, viral exanthems, and atopic dermatitis
• Crusted scabies: Psoriasis, contact dermatitis, eczema, and Darier’s disease

• Treat all family members and close contacts simultaneously
• Patients and contacts should be advised to cut nails and take bath in hot water at night, wipe dry and then apply the medication from behind the ears and below the chin over the entire body.
• In children aged less than two years, face and scalp to be included.
• It should be left overnight (8–12 hours) and the next day morning, hot water bath should be taken.
• Clothing and bed linen should be washed in hot water and dried in sunlight.
• This procedure has to be repeated after one week.
• Antiscabicidal agents:
  • 5% permethrin cream (safe from 2 months of age)
  • 1% gamma benzene hexachloride (not used in children below 2 years)
  • 10% crotamiton cream
  • 3–6% precipitated sulfur can be applied for three consecutive nights in infants who are <2 months old, bath should be given 24 hours after the last application.
  • Topical ivermectin has also been prescribed. Systemic ivermectin is used in children aged >5 years at 200 µg/kg body weight. The second dose to be given after 1 week. Antihistamines to be continued for 2–4 weeks, as the itching persists in scabies posttreatment due to the delayed hypersensitivity reaction.

• Achromic pityriasis versicolor—well-defined hypopigmented macules and patches. One can stretch the skin and see if the border is well made out. The use of a magnification lens facilitates the differentiation.
• Polymorphic light eruption—scaly condition, commonly seen on the face, associated with itching after exposure to sunlight, seen as a rim of hypopigmentation around the hyperpigmented patch
• Early vitiligo
• Indeterminate Hansen
• Postinflammatory hypopigmentation

• General measures of photoprotection between 9 AM and 4 PM such as the use of covered clothing (loose, long, sleeve shirts, and pants), broad-brimmed hat, and umbrella.
• They should be advised to apply broad-spectrum sunscreens 30 minutes before exposure to the sun.
• If the lesion is on the face, desonide cream could be applied twice a day for 2 weeks. If the lesion is on the forearm, fluticasone or mometasone cream could be applied at night for 2 weeks.
• Antihistamines may be given if itching is troublesome.

• Grade 1 (mild): Open and closed comedones with few inflammatory papules and pustules
• Grade 2 (moderate): Papules and pustules, mainly of the face
• Grade 3 (moderately severe): Numerous papules and pustules and occasional inflamed nodules, also on the chest and back
• Grade 4 (severe): Many large painful nodules and pustules

• Mild acne:
  • Comedonal: Topical adapalene
  • Mixed/few papular/pustular: Topical adapalene + topical antimicrobial (Clindamycin)
• Moderate:
  • Mixed/papular/pustular: Topical retinoid + Benzoyl peroxide + Oral doxycycline
  • Nodular: Topical retinoid + Benzoyl peroxide + Oral azithromycin pulse—3 days a week
• Severe acne:
  • Nodular: Oral isotretinoin

• Onset at an early age
• Multiple patches with rapid progression
• Ophiasis, sisaipho, alopecia totalis, and alopecia universalis
• Family history
• Associations—autoimmune conditions, atopic dermatitis, Down syndrome, and nail dystrophy
• Poor response to treatment in the past

• First and foremost, children with alopecia areata should be counseled and reassured, as it is associated with low self-esteem and peer bullying.
• Topical corticosteroid: In this child, mometasone ointment could be applied once a day for 4 weeks with monitoring.
• Other topical treatment options include contact sensitizers, minoxidil, tacrolimus, and anthralin
• Multiple patches/ophiasis/sisaipho—systemic therapy—oral corticosteroids, cyclosporine, methotrexate, and tofacitinib

• Ash leaf macules—seen at the time of birth, single or multiple, oval or may have broad end on one side and tapering on other side.
• Angiofibromas—seen after birth or later in age, firm red brown discrete telangiectatic papules commonly seen over the nasolabial furrow, cheeks, and chin area.
• Shagreen patch—seen over the lumbosacral region as soft elevated, skin-colored plaque with elephant hide or orange-peel appearance.
• Molluscum pendulum—large, soft, and pedunculated papules resembling large skin tags are seen over the axillae, neck, and inguinal folds.
• Periungual fibromas (Koenen’s tumor): Fibromatous tumors of gum, palate, tongue, larynx, and pharynx that appear at or after puberty.
• Enamel pits over the teeth and poliosis are seen.

• CNS: Mental retardation, epilepsy, behavioral disorders, and psychotic symptoms. Subependymal nodules and giant cell astrocytomas occur.
• OCULAR: Hypopigmented spots in iris, pigmentary abnormalities of retina, and retinal phacomas occur.
• CVS: Rhabdomyomas and Wolff–Parkinson–White syndrome in cardiovascular system.
• Renal: Angiomyolipomas and cystic renal disease may be associated.
• Pulmonary: Recurrent pneumothorax, chylothorax, and lymphangiomyomas.
• Gastrointestinal tract (GIT): Colonic polyps

• Stage 1: Inflammatory stage starts after birth or within 8 weeks of life and may last for 4–18 months and disappear. Vesicular lesions with erythematous base are seen commonly over limbs and trunk.
• Stage 2: Verrucous stage appears within first few months of life as first stage disappears. Warty papules and plaques are seen along the lines of Blaschko’s lines.
• Stage 3: Hyperpigmented stage is seen from 6 months to 1 year as second stage disappears. It is located over trunk, axilla, and groin in the form of whorled slate gray hyperpigmented plaques and most of the lesions disappear by adolescence.
• Stage 4: It is seen over the posterior calves and arms as pale, hairless linear patches, and plaques.
• In the hair, vertex alopecia in a milder form and rarely agenesis of eyebrows and eyelashes may occur. Nail changes—nail dystrophy, ridging, and pitting. Subungual and periungual keratotic tumors present between puberty and third decade of life. Microdontia, anodontia, hypodontia, peg-shaped teeth, and delayed eruption of permanent teeth may occur.

• XPA: It codes for DNA damage-binding protein 1 (DDBP1) on chromosome 9q22, presents with skin and neurological disease.
• XPB: It codes for excision repair cross-complementing 3 (ERCC3) on chromosome 2q21. It correlates with Cockayne syndrome and trichothiodystrophy.
• XPC: It codes for endonuclease on chromosome 3p25. Mutated endonuclease is unable to sense the damage to DNA which results in sun sensitivity and malignant tumor formation. No neurological involvement.
• XPD: It codes for ERCC2 and is on chromosome 19q13. It correlates with Cockayne syndrome and trichothiodystrophy.
• XPE: It codes for DDB2
• XPF: It codes for ERCC4 and is on chromosome 16p13.
• XPG: It codes for ERCC5 and is on chromosome 13q33.
• XPV: It is a variant in mutation of XP, not involved in nucleotide excision repair but is involved in postreplication repair, and codes for polymerase in chromosome 6p21.

• Cutaneous features include freckles and dryness occurring over the face, hands, neck, and other sun-exposed areas.
• Irregular patches of pigmentation due to fusion of freckles occur
• Angiomas and telangiectasias are common along with atrophic patches.
• Vesiculobullous lesions over the sun-exposed areas are common and when it heals it can lead to scars, contractures, and disfigurement.

• Paucibacillary leprosy: Monthly supervised dose of capsule rifampicin 450 mg and tablet dapsone 50 mg on day 1, followed by daily dose of dapsone 50 mg from day 2 to 28, for 6 months.
• Multibacillary leprosy: Duration—1 year; Monthly supervised dose of capsule rifampicin 450 mg, tablet dapsone 50 mg and capsule clofazimine 150 mg on day 1, followed by daily dose of dapsone 50 mg and alternate day dosage of clofazimine 50 mg from day 2 to 28.
• In children younger than 10 years, weight-based dosage has to be given:

• Antiepileptics (phenytoin, carbamazepine, valproic acid, phenobarbital, and lamotrigine)
• Nonsteroidal anti-inflammatory drugs
• Antibiotics (commonly trimethoprim with sulfamethoxazole, aminopenicillins, tetracyclines, and cephalosporins)
• Immune check point inhibitors (nivolumab and pembrolizumab)

• Hapten/prohapten concept suggest that drugs will covalently bind to proteins in serum, forming complexes. These complexes are recognized by certain human leukocyte antigen (HLA) molecules and presented to T cells triggering an immune response.
• Pharmacological interaction concept—chemically inert drugs directly bond to HLA molecules, leading to T-cell activation.
• The altered peptide concept says that drug binds inside HLA-binding pockets altering self-protein presentation to T cells. Hence, they are not recognized as self, prompting an immune response. Keratinocyte death was mediated by Fas ligand interacting with Fas receptor on the keratinocyte surface.
• Recent studies have identified granulysin as an important factor in apoptosis.

• Cessation of the causative drug
• Fluid and electrolyte management
• Infection control and wound care
• Role of corticosteroid as monotherapy is controversial.
• Intravenous immunoglobulin (IVIg) alone in the treatment is controversial. Combination of IVIg and corticosteroids are beneficial.
• Use of cyclosporine with or without steroids
• IVIg with plasmapheresis and etanercept has better outcome.

• Prodrome of fever, fatigue, and irritability as the Staphylococcus localizes in the conjunctiva, nose, throat, etc.
• Within 1–2 days, tender erythematous patches occur over face, axilla, groin, and neck.
• A few hours later, fragile blisters develop and the fluid inside the blister may be sterile or pus.
• These blisters enlarge and form bullae which rupture and cause desquamation
• The skin appears wrinkled due to the formation of flaccid bulla which is called sad man facies.
• A positive Nikolsky sign may be present.
• Skin heals without scarring within 2 weeks. Sometimes biopsy is performed to prove the diagnosis.

• Penicillinase-resistant penicillins—nafcillin or oxacillin, 100–150 mg/kg/day is given intravenous in four divided doses with a maximum dose of 12 g/day.
• Cefazolin 50–100 mg/kg/day in three divided doses can be given. 2 g of cefazolin intravenous given every 8 hours.
• Vancomycin 45 mg/kg/day in three divided doses with a maximum dose of 2 g/day
• When clinical improvement occurs, systemic therapy is stopped and oral antibiotics such as cephalexin or dicloxacillin are given. The total duration of antibiotic therapy is for 10 days.
• Intravenous fluids to prevent dehydration
• Rarely IVIg in a dose of 0.4 g/kg/day can be given for 5 days. Impetigo is treated with topical mupirocin/fusidic acid.

a. Neurofibromatosis (NF)

b. Autosomal dominant with complete penetrance

• Neurofibromatosis type 1 (NF1) is due to de novo or inherited loss-of-function mutation of the NF1 gene located on 17q11.2.
• NF type 2 (NF2) is due to loss-of-function mutation of the NF2 gene located on 22q12 and codes for merlin.

c.

• Skin: Dermal and plexiform neurofibroma, café au lait macules, and axillary and inguinal freckling; rarely juvenile xanthogranuloma and nevus anemicus. Learning disabilities, both verbal and nonverbal disabilities may occur.
• Ocular: Plexiform neurofibroma, Lisch nodules, optic gliomas, and choroidal nodules occur. Brain tumor in the form of pilocytic astrocytomas is one of the common intracranial neoplasms.
• Skeletal: Bone dysplasias, pectus deformity, scoliosis or kyphosis, and anteromedial bowing of legs can occur. Sphenoid wing dysplasia, non-ossifying fibromas, short stature, headaches, macrocephaly, and rarely hypertension can occur.

d. Diagnostic criteria for neurofibromatosis type 1: Must have two or more of the following:

• Six café au lait macules that measure >0.5 cm in prepuberty and >1.5 cm in adults
• Freckling of the axillary and/or inguinal areas
• A plexiform neurofibroma or two or more neurofibromas
• Two or more Lisch nodules
• Pathognomonic skeletal dysplasia—tibial or sphenoid wing dysplasia
• An affected first-degree relative

Criteria for neurofibromatosis type 2:

• Bilateral vestibular schwannomas seen by magnetic resonance imaging (MRI) scan
• A first-degree relative with NF2 or any two of the following: schwannoma, meningioma, glioma, neurofibroma, and posterior subcapsular lenticular opacities.
• Unilateral vestibular schwannoma and any of the following: schwannoma, meningioma, glioma, neurofibroma, and posterior subcapsular cataract.
• Multiple meningiomas with unilateral vestibular schwannoma or any two of the following: glioma, schwannoma, and posterior subcapsular cataract.

e.

• Complete physical examination twice a year which includes height, weight, head circumference, blood pressure, and observation for bony abnormalities, and ophthalmological examination.
• Monitoring for learning disabilities and early intervention
• Methylphenidate is useful in attention deficit problems in children with NF1.
• Dermal neurofibromas may be excised particularly when disfiguring
• Imatinib has been tried to decrease the progression of plexiform neurofibromas.
• In case of pain associated with plexiform neurofibromas, sirolimus has helped.
• Genetic counseling

• Topical application of miconazole cream twice daily over the patch and 2 cm beyond the lesion
• Oral griseofulvin (10 mg/kg) divided in two doses after a fatty meal for 6 weeks for better absorption. Steroid modified tinea needs to be treated for a longer duration.
• Good personal hygiene and following the general measures in the management of tinea
• Treatment of infected family members

• Gray patch—psoriasis and seborrheic dermatitis. There is no hair loss in these two conditions.
• Kerion—bacterial abscess
• Alopecia areata-like—alopecia areata
• Patchy hair loss—trichotillomania (loss of hair in accessible areas with hair being of varying lengths) and traction alopecia

• Saline compresses
• Frequent application of emollients
• Topical corticosteroids to be prescribed for a period of 2 weeks—desonide cream for the face and flexures; fluticasone cream for the few lesions on the trunk.
• Antibiotics: Cephalexin for 5 days and antihistamines
• Child to be reviewed after 2 weeks. Subsequently depending on the response, topical corticosteroids may be slowly tapered and topical tacrolimus 0.03% may be introduced.