7.3 Skin Diseases & Disorders of the Hands and Feet

Key Takeaways

  • OAC 4713-15-13(A) bars any service on a client with visible swelling, eruption, redness, bruising, rash or parasitic infestation in the service area without written permission from a physician.
  • A callus (keratoma) is diffuse hyperkeratotic thickening and a corn (heloma) is focal with a hard central core; both may be smoothed with abrasives and neither may be reduced with a bladed implement.
  • Allergic contact dermatitis to uncured acrylates is immune-mediated and permanent, and typically appears at the fingertips and at the eyelids, face and neck.
  • Nail psoriasis produces pitting, oil-drop discolouration, onycholysis and subungual hyperkeratosis and is frequently mistaken for fungal infection; a manicurist cannot distinguish them and must refer.
  • A new, widening, single-digit pigmented band, especially with pigment spreading onto surrounding skin, must be referred promptly and never concealed with polish.
Last updated: September 2026

Skin Diseases and Disorders of the Hands and Feet

Ohio State Board Exam Alert: "Skin Diseases/Disorders" is a named leaf under the 20 % Anatomy & Physiology domain, sitting alongside skin structure and skin function. Ohio pairs it with a hard legal rule: OAC 4713-15-13(A) bars any service on a client with visible swelling, eruption, redness, bruising on skin, rash, or parasitic infestation in the service area without written permission from a physician. Recognition plus refusal is the tested behaviour — never diagnosis.

A manicurist sees more hand and foot skin than most clinicians do. That makes recognition a professional duty, and it makes the boundary sharp: you learn these conditions in order to know when to stop, not in order to name a disease to a client.


1. The Vocabulary of Skin Lesions

Examination items often describe a lesion rather than name a disease, so the vocabulary matters.

Primary lesions

LesionDescriptionNail-salon example
MaculeFlat, discoloured spot, no elevationFreckle; a flat age spot on the dorsum of the hand
PapuleSmall solid raised lesion, no fluidAn early wart; an insect bite
VesicleSmall blister containing clear fluidContact dermatitis blister; early herpes
PustuleRaised lesion containing pusAcute paronychia at the nail fold
WhealItchy raised area from an allergic reaction or biteHives after a product reaction
TubercleSolid abnormal mass larger than a papuleA nodule under the skin
CystClosed, abnormally developed sac containing fluid or semi-solid matterDigital mucous cyst near the eponychium

Secondary lesions

LesionDescriptionNail-salon example
ScalePlate of dry or greasy flakesPsoriasis; chronic tinea pedis
CrustDried mass of serum, blood or pusHealed scratch; impetigo
ExcoriationSore or abrasion from scratching or scrapingOver-filed skin at the sidewall
FissureCrack in the skin penetrating into the dermisSplit heel; cracked knuckles
UlcerOpen lesion with loss of skin depth and often fluid or pusDiabetic foot ulcer — an absolute stop
Scar / cicatrixFibrous tissue after an injury healsOld matrix injury
Keratoma / callusThickened patch of epidermis from pressure or frictionCallus on the heel or ball of the foot

Hyperkeratosis is the general term for a thickening of the stratum corneum. A callus (keratoma) is diffuse thickening; a corn (heloma) is a focal, cone-shaped thickening with a hard central core that presses inward and causes pain. Both are pressure responses. Both may be smoothed with abrasives, and neither may be pared with a blade — OAC 4713-1-07(G)(1) makes use of a bladed implement to remove skin cells below the stratum corneum an out-of-scope act.


2. Inflammatory and Allergic Conditions

ConditionPresentationSalon response
Irritant contact dermatitisDry, red, cracked, sometimes fissured skin from repeated chemical or wet exposure; no immune memory — anyone gets it with enough exposureExtremely common in technicians. Barrier creams, nitrile gloves, warm not hot water. On a client, refuse service to an affected area without written physician permission
Allergic contact dermatitisRed, itchy, sometimes vesicular reaction confined initially to contact sites — classically the fingertips, eyelids and neck of a client sensitised to uncured acrylate; immune-mediated and permanent once establishedStop using the product on that client. Sensitisation to HEMA and other acrylates is the profession's most significant occupational allergy. Refer for medical assessment
Eczema (atopic dermatitis)Chronic, itchy, dry, inflamed patches, often on flexural skin and handsService only if the treatment area is clear; a flare in the service area triggers OAC 4713-15-13(A)
PsoriasisSharply demarcated red plaques with silvery scale on elbows, knees, scalp and hands; nail changes are common — pitting, oil-drop discolouration, onycholysis, subungual hyperkeratosisNot contagious, but scaling, cracked, bleeding plaques in the service area require written physician permission. Nail psoriasis is frequently mistaken for fungal infection; a manicurist may not distinguish them — refer
Urticaria (hives)Transient wheals, often with a known triggerStop, note the trigger, refer if severe or if breathing is affected

3. Infectious Skin Conditions a Nail Technician Meets

ConditionOrganismRecognitionContagious?
Tinea pedis (athlete's foot)Dermatophyte fungiItching, scaling and maceration between the toes; dry moccasin-pattern scaling on the soleYes — spores survive on floors, mats and basins
Tinea manuumDermatophyte fungiDry scaling of one palm, often with tinea pedis on both feetYes
Tinea corporis (ringworm)Dermatophyte fungiAnnular red patch with a raised, scaly, advancing border and central clearingYes
ImpetigoStaphylococcus aureus / Streptococcus pyogenesSuperficial vesicles and pustules rupturing to a honey-coloured crustHighly
CellulitisS. aureus / S. pyogenesSpreading hot, red, tender, swollen area with poorly defined edges, often with feverNot by casual contact, but a medical emergency — refer immediately
Herpes simplex / herpetic whitlowHSVPainful grouped vesicles; on a finger it produces an intensely painful whitlowYes — direct contact
Verruca (common wart)Human papillomavirusRough, raised, cauliflower-textured papule; plantar warts grow inward on the sole and often show punctate black dotsYes
ScabiesSarcoptes scabiei miteIntense night-time itching, burrows in finger webs and wrists, papular rashYes — direct and prolonged skin contact
PediculosisLiceItching and visible nitsYes

Every condition in this table is a stop. The Ohio rule does not require you to determine whether it is contagious, only to observe swelling, eruption, redness, bruising, rash or parasitic infestation in the service area and to obtain written physician permission before proceeding.


4. Pigmentation and Growth Changes

ChangeNotes for a nail technician
Lentigines / age spotsFlat brown macules from cumulative sun exposure on the dorsum of the hand. Harmless, but a reminder that UV/LED lamp exposure is a real if small dose
Hyperpigmentation / hypopigmentationPost-inflammatory darkening or lightening after injury or dermatitis
VitiligoPatchy loss of pigment; not contagious; those areas burn readily
Nevus (mole)Any mole that changes in size, shape, colour, border or symmetry, or that bleeds, warrants prompt medical review
Longitudinal melanonychiaA pigmented band running the length of the nail. It has benign causes, but a new, widening, single-digit band, especially with pigment spreading onto the surrounding skin, must be referred urgently and never concealed with polish

A manicurist does not diagnose any of these. What a manicurist does is notice a change, decline to cover it up, and say clearly that a physician should look at it.


5. The Refusal Script

Handling a refusal well protects the client, the salon and the licence.

  1. Observe and describe, do not name. "I can see some redness and cracking between these toes."
  2. State the rule, not a judgement. "Ohio's board rules don't let me work over that area without written permission from a physician."
  3. Refer specifically. A physician, a dermatologist or a podiatrist — never a product.
  4. Offer what you can lawfully do. Service the unaffected hand or foot if the condition is localised and you can work without cross-contact, or rebook.
  5. Decontaminate. OAC 4713-15-13(D) requires that every area and item of equipment that contacted the affected individual be cleaned and disinfected with an appropriate disinfectant.
  6. Document. Note the observation, the refusal and the referral on the client record.

Exam trap: an option in which the technician "explains that the client has a fungal infection and recommends an over-the-counter antifungal" fails twice: it is a diagnosis, and it is a treatment recommendation. Both are barred by OAC 4713-8-07(D).

Test Your Knowledge

A pedicure client has itching, scaling and maceration between the fourth and fifth toes of both feet. What is the correct sequence of actions for an Ohio manicurist?

A
B
C
D
Test Your Knowledge

Which description correctly distinguishes a callus from a corn, and what may a manicurist lawfully do about either?

A
B
C
D
Test Your Knowledge

A long-standing client returns with a single dark brown band running the full length of her right thumbnail. She says it appeared a few months ago and looks wider than it was, and asks for a dark polish to hide it. What should the manicurist do?

A
B
C
D
Test Your Knowledge

Which lesion definition is correct?

A
B
C
D